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An imaginary line drawn through the center of the length of the central nervous system, from the bottom of the spinal cord to the front of the forebrain
With respect to the CNS (and neuraxis), located near or toward the head (Rostral).
With respect to the CNS (and neuraxis), located near or toward the tail (Caudal).
“Toward the beak”; with respect to the central nervous system, in a direction along the neuraxis toward the front of the face. (Anterior)
“Toward the tail”; with respect to the central nervous system, in a direction along the neuraxis away from the front of the face. (Posterior)
“Toward the back”; with respect to the central nervous system, in a direction perpendicular to the neuraxis toward the top of the head or the back.
“Toward the belly”; with respect to the central nervous system, in a direction perpendicular to the neuraxis toward the bottom of the skull or the front surface of the body.
The CNS is encased in bone: The brain is covered by the skull, and the spinal cord is encased by the vertebral column.
Peripheral Nervous System (PNS)
- Mass of neurons, glia, and other supporting cells
- Encased in a tough, bony skull and floating in a pool of cerebrospinal fluid.
- Chemically guarded by the blood–brain barrier.
- Receives approximately 20 percent of the blood flow from the heart, continuously
- The outermost layer of the meninges.
- It is thick, tough, and flexible but unstretchable
- Surrounds superior sagittal sinus vein
- Keeps brain from collapsing when we stand
- Closely attached to the brain and spinal cord, and following every surface convolution.
The smaller surface blood vessels of the brain and spinal cord are contained within this layer
Gap between the pia mater and arachnoid membrane filled with a liquid called cerebrospinal fluid (CSF).
The outer and inner layers (dura mater and pia mater) fuse and form a sheath that covers the spinal and cranial nerves and the peripheral ganglia of the PNS.
- A clear fluid that is extracted from the blood and resembles blood plasma, that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and spinal cord.
- Reduces the shock to the central nervous system that would be caused by sudden head movement.
- Produced continuously.
- Total volume of CSF is approximately 125 ml, and the half-life is about 3 hours
- The ventricle located in the center of the diencephalon (down center of brain along midsagittal plane)
- Located in the center of the telencephalon
A bridge of neural tissue that crosses through the middle of the third ventricle.
A long tube that connects the third ventricle to the fourth ventricle, located in the center of the mesencephalon
The ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon
- Prduced by the choroid plexus of the lateral ventricles, flows into the third ventricle where more CSF is produced, then flows through the cerebral aqueduct to the fourth ventricle, where still more CSF is produced.
- The CSF leaves the fourth ventricle through small openings that connect with the subarachnoid space surrounding the brain.
- The CSF then flows through the subarachnoid space around the central nervous system, where it is reab- sorbed into the blood supply through the arachnoid granulations (pouch-shaped structures) that protrude into the superior sagittal sinus (a blood vessel that drains into the veins serving the brain)
When the walls of the ventricles expand due to an interruption in the flow of CSF (i.e. a brain tumor growing in the midbrain may push against the cerebral aqueduct, blocking its flow, or an infant may be born with a cerebral aqueduct that is too small to accommodate a normal flow of CSF.) This results in greatly increased pressure within the ventricles, because the choroid plexus continues to produce CSF.
Usually when one of the meninges is inflamed, they all are.These result in very quick and noticeable results. Changes nervous system function quickly.
-Cerebral aqueduct (Mesencephalo)
Neuron cell bodies predominate, giving a grayish tan appearance.
White matter (Beneath the cerebral cortex):
Millions of axons that connect the neurons of the cerebral cortex with those located elsewhere in the brain have a large concentration of myelin and gives this tissue an opaque white appearance
- outermost layer cerebral hemispheres
- consists mostly of glia and the cell bodies, dendrites, and interconnecting axons of neurons, making up gray matter.
- conscious mind: motor, sensory, perception, cognition, and association areas
- Contain sulci (small grooves), fissures (large grooves), and gyri (bulges between adjacent sulci or fissures)
the outermost layer of the cerebral hemispheres.
Left hemisphere damage=depression
Right hemisphere damage=surprisingly cheerful
- receives visual information
- located at the back of the brain, on the inner surfaces of the cerebral hemispheres—primarily on the upper and lower banks of the calcarine fissure (A fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks)
primary auditory cortex
primary somatosensory cortex
Normally hidden from view by the frontal and temporal lobes, receives information concerning taste.
primary motor cortex
Primary sensory and motor cortex occupy only a small part of the cerebral cortex. The rest accomplishes perceiving, learning/remembering, planning, & acting in association areas
- Central sulcus (separates frontal from parietal lobe) provides dividing line b/w rostral (involved in movement-related activities, such as planning and executing behaviors) and caudal regions (involved in perceiving and learning of the cerebral cortex)
Motor Association Cortex (akaPre-Motor Cortex)
- Rostral (in front of) the primary motor cortex. This region controls the primary motor cortex; thus, it directly controls behavior by organizing the movements that you’re going to do.
- Each primary sensory area of the cerebral cortex sends information to these adjacent regions
- Analyze the information received from the primary sensory cortex (perception, and memories)
- Region closest to the primary visual cortex analyzes visual information and stores visual memories.
- Regions far from the primary sensory areas receive information from more than one sensory system; thus, make it possible to integrate information
- left hemisphere analyzes information - the extraction of elements that make up the whole of an experience, recognizes serial events and controls sequences of behavior. verbal activities, such as talking, understanding speech, reading, and writing
- right hemisphere is specialized for synthesis, putting isolated elements together to perceive things as a whole. (ability to draw sketches (especially of 3D objects), read maps, and construct complex objects out of smaller elements
a large band of axons that connects corresponding parts of the cerebral cortex of the left and right hemispheres
- The neocortex includes the cerebral cortex that covers most of the surface of the cerebral hemispheres (including the frontal, parietal, occipital, and temporal lobes)
- The limbic cortex, is located around the medial edge of the cerebral hemispheres. The cingulate gyrus is an important region of the limbic cortex.
a set of interconnected brain structures formed a circuit whose primary function is emotion, memory, motivation, and sense of smell
-the limbic cortex, the hippocampus and the amygdala (“almond”), located next to the lateral ventricle in the temporal lobe.
- Acts to inhibit emotions. Tells us if we hate/like things, that we should stop liking things (tells us to stop if we’re eating too much chocolate).
- Processes both social and physical pain
- Sexual drive, feeding behavior (primitive drives)
This part helps you think about what you’re going to. Is right beside motor skills so that you can then execute.
The more powerful your inferior frontal is, means you have better control over your impulsivity.
Dopamine being at too high of levels in this area – found in gamblers.
Involved in Theory of Mind (religion)
Motor cortex controlling face and throat is right behind this area.
This is a very vulnerable part of the brain, common problem area for strokes.
Can lose separate languages if you learn languages differently.
Voices/music heard by schizophrenics.
Causes visual hallucinations. Right next to occipital lobe, processes what you are looking at. Recognizes what you’re seeing.
Integrates the sensory systems into a single “world view” that is unique for each person.
Integrates sensory systems. Vision, hearing, touch, all come together and seem seamless.
Inherited abnormal neuronal connections in the inferior prefrontal cortex may underlie an increased risk of developing stimulant drug dependence.
- Bottom of brain, hovers at top of nasal cavity.
Blood comes from heart through internal carotid artery.
Humans also get small amount thru vertebral artery (dogs and cats get much more thru here)
Circle of willis – allows blood to flow from one side of brain to next.
Then divides into Posterior Cerebral Artery, Anterior Cerebral Artery, and Middle Cerebral Artery (most associated with clogs and problems bc biggest)
Hemorrhagic – weakening in wall, blood bleeds out.
Emotional disturbances – like bipolar disorder can be detected by observing the cingulate gyrus.
Cingulate gyrus is not as big or thick in people who suffer from bipolar disorder (trouble controlling emotion)
Tumor pressing against cingulate cortex – hypersexual nun.
Impulsivity – disorder with cingulate cortex.
Emotions experienced: fearWithout healthy amygdala: impaired ability to associate neutral and aversive stimuli
-Top of spinal column, switchboard of brain.
Projects outward, out of thalamus to rest of brain to wake you up.
Immature Thalamus = ADHD
Hearing, then speaking it (mirroring)
Allows you to mimic and learn language.
Allows you to read out loud
Help us move better. We can move without it but this perfects it.
Motor skills that are learned and stored in cerebellum (performing repetitive motor skills like signing your name or swinging a bat/golf club).
Glucose is the brain’s primary source of energy and most of it is used to maintain a resting membrane potential – critical for neuronal function.
Neurons use a lot of DNA - Large nuclei
2 most glucose dependent cells in body are neurons and cancer cells.
Lots of mitochondria, neurons don’t have ability to store energy.
Important component to blood-brain barrier.
Astrocytes conduct nutrients from the blood to the neurons and transport waste products away to the blood and CSF. Live b/w blood vessels and neurons. Fatty substance so polar things must be transported.
Fill and cover surfaces of blood vessels. Very dense. 10-15 astrocytes for every neuron. Non-overlapping. Each astrocyte occupies a distinct volume (domain) with very little or no overlap with the volumes (domains) occupied by other astrocytes.
95% of all tumors are from glia.
Glia tumors are common and form as spheres or gather around an artery or something. Don’t go far, concentrated. Grow very slowly, don’t really spread. Glia/astrocytes are the only brain cells that form cancer.
Phagocytosis of synaptic structures during postnatal development, phagocytosis of newborn neurons during adult neurogenesis, active remodeling of the perisynaptic environment and release of soluble factors in the mature and aging brain. Influence neuronal plasticity and function, may be regulated by sensory experience. Help synapses form and disappear. Test to see if anything is wrong. If they sense anything is wrong they can initiate an immune response. Protection and recovery.
have a complete array of proteins floating on their surface that allow them to attach to the pre-synaptic membrane and be prepared to eject their contents.
Synapse on soma (cell body) – much more influential than those on dendrites.
Can be on spine or dendritic shafts
Can be on another axon.
Could have millions synapses attached to one neuron.
A Transmitter - important for paying attention – glucose and mitochondria needed to produce acetylcholine
Making the connection larger and larger by “using” it.
Usage can eventually make 2 connections.
You can sever the connections for things you don’t want to remember.
More “plastic” when you have less connections (youth), but inefficient.Adult brains are more efficient, but less flexible.
studies of groups of subjects who have been exposed to the conditions of interest in the real world. Not true experiments because confounding variables are not controlled.
Chronic brain damage resulting from repeated concussion, often found in boxers and football players. Typical Symptoms: Slurred Speech, Awkward gait, Slowed thought processes, lack of emotional and behavioral control.
advance form of syphilis that effects the spinal cord, leads to lose of sensation to the bottom of the feet. Individual ends up walking funny
Patient stands upright and closes eyes, if they fall then there is something wrong with the cerebellum.
Tumor in Basolateral Amygdala
Threadlike structure containing genes in the nucleus of each cell. Occur in match pairs.
destruction of brain tissue either naturally or experimentally.
applies strong and quickly changing magnetic fields to surface of skull that can interrupt brain function. rTMS successfully used to temporarily change brain activity immediately below stimulation site: schizophrenia, depression
9-14 Hz. Relaxed/reflecting—awake and relaxed=8-12Hz
testable (yes/no) prediction that is used to guide further research
study of microscopic structure and tissue. Labeling tissues to see diff structures. Tissue must be fixed by freezing in formaldehyde, sliced thinly, mounted on miscroscpe slides, stains applied to highlight structures of interest. Nissl stain: cell bodies of neurons. Golgi stain:single cells, darkly stains neuron. Meylin stain: stains meyling that wraps and insulates axons to identify neural pathways.
part of pons, regulates arousal, sleep awake cycles. Pain modulation. Fliter out background info.
o Parkinsons Disease, Huntingtons Disease, ADHD,OCD, Tourettes
connects different parts of the brain. Axons (highways)
areas capable of integrating sensory input with motor output
defines boundary of cell. Intracellular/extracellular. Double layer of fat molecules. Let things in and out. Contains protein molecules.
non neural. 9x more numerous than neurons. Provide physical and functional support to neurons. Clinical implications?
Ø mostly K, some Na, some Cl-
The neuron is polarized in it’s resting state at ‐70mV. Resting membrane potential due to: selective permeability of membrane, and uneven distribution of ions inside vs outside of the cell.-Higher sodium outside, Higher potassium inside, due to action of sodium-‐potassium pumps
1.when AP invades here, signal changes from electrical to chemical. 2. Calcium channels are opened allowing Ca2+ ions in. T3. his causes the synaptic vesicles to release microtubules--exocytosis. 4. Vesicles fuse with membrance at relsease sites. 5. Vesciles open, releasing neurotransmitters into synaptic gap. 6. Vesicle material is then recycled: 7. either return to cell body via retrograde transport, or refilled at terminal. Note: calcium must be cleared prior to arrival of next AP.
1. Diffusion-most passive way to emit NT
2. Deactivate Enzymes- enzymatic degradation. in in acetocolene, important for motor neuron junctions.
3. Reuptake- the receptors in the presynaptic cell grab onto NT and are taken back into cell for reuse.
Reuptake inhibitors of seratoinin prevent it from being taken up, so it stays longer to do more of its job. MAO inhibitors prevent the breakdown which allows it to be packaged back up into vesicles and released again.
maternal care, bonding
What is split brain surgery? Why is it performed? What did individuals with split brain surgeries teach us about lateralization of function in the brain?
pathways connecting two hemispheres(corpus callosum) severed in order to control seizures. There is no change in personality, intelligence, or speech. Tells us that the brain is actually two separate minds.
What functions are specialized more to one side of the brain than the other?
Left hemisphere is logical, sequential, verbal.
Right hemisphere is emotional, intuitive, spatial relations.
What is the possible purpose of lateralization? What do savants tell us about the role of lateralization?
May allow organisms to simultaneously attend to different aspects of environment—perhaps at the expense of superior ability at a given task. Lateralization of function is high in savants: injury to one hemisphere leads to increased contralateral hemisphere function, compensation, ability à INCREASED LATERALIZATION. Right hemisphere = loss of big picture. Left hemisphere=loss of local details
What is language?
system of rule-based communication that combines symbols (sounds and gestures) in order to express a meaning, idea, or thought. Transmit info, express thoughts and emotions, automatic, complex, and coordinated. Use of vocalization to communicate, no connection between symbol and what is signifies, passed from generation to generation, communication must follow social rules, can communicate about objects ane events that are distant in time and place.
What is the brain evidence that non‐human primates may be capable of language?
What are the main brain regions involved in language? Know the flow of information through the language circuit
1. Information about sound is analyzed by the primary auditory cortex and transmitted to Wernicke’s area. 2. Wernicke’s area analyzes the sound information to determine the word that was said. 3. Under connectionalist model, the info is transmitted via arcuate fasciculus—some research casts doubt here. 4. Broca’s area forms motor plan to repeat the word and sends that info to motor cortex. 5. Motor cortex implements the plan, manipulating the larynx and related structures to say the word.
damage to the arcuate fasciculus prevents the patient from directly transferring speech sounds from Wernicke’s area to Broca’s area. The patient will have considerable difficulty repeating words, phrases, and sentences. Indirect connections between stored meanings of words and Broca’s area allow patient to speak fairly normally. Fluent aphasia, good understanding of language unspoken and written.
What is dyslexia? What are the main abnormalities in the brain of dyslexic individuals?
Multiple rythms can be expressed within a system
Ultradian- less than 24h, activity.
Cicadian- any rhythmic change that continues at close to a 24 hr cycle in the absence of external cues. approximately 24h, sleep-wake cycle, body temp, cortisol secretion. In humans its about 24.2 to 24.9 hrs.
Infradian-greater than 24h, menstrual cycle
Cicannual- greater than 24 hr, migration
What is the name of a biological rhythm that is approximately 24 hours? Approximately 1 year? Know an example of each.
Circadian- 24 hrs. sleep/wake. Body temp. cortisol secretion
Circannual- yearly, migration
What is the length of the sleep‐wake cycle in humans? Is this true for all species?
24.2-24.9h, not true for all species: Tau: 23.8
What is entrainment versus free‐running? What is a zeitgeber and how does it relate to entrainment versus free‐running?
Entertainment-the process of resetting the biological clock(or keeping it aligned).
Zeitgeber- the stimuli that an organism uses to synchronize with the environment. “time-giver”--without this, drift occurs.
free-running- dark light and let sleep go on its normal pattern. What brain naturally does when no light cues. A rhythm not synchronized to environmental time cues.
What is the brain region that acts as our endogenous biological clock? Where is it located? From where does this brain region get its information about the external zeitgeber, LIGHT? What is the name of this neural projection?
Superchaismatic Nucleus(SCN)- mammalian master biological clock. Located about the optic chiasm in hypothalamus. The pacemaker of circadian endogenous(uncued) rhythms. Incorporates more 2-deoxyglucose during light period. Electrically more active during light period of cycle. Rhythmic in the absence of inputs/outputs—intrinsic rhythm. light info goes from the eye to the SCN via the retinohypothalamic pathway.
Does the SCN require external light information to keep a roughly 24 hour cycle? What happens without external light cues?
Does not require external light info, it has an intrinsic rhythm. Light participates in triggering some of these protein fluctuations—which serve as the “ticking” of the internal clock.
What hormone is important for keeping the circadian rhythm entrained to external light cues? When is this hormone at high levels, and when is it low?
Mealanin is the hormone of darkness released by the pineal gland.Melatonin is low during the day and at its peak at 4am. Cortisol is high in the early morning—involved in high bp, higher heart rate, and mobilization of body’s energy stores.
What happens to circadian rhythms during jet lag and why? Is it easier to travel to a new time zone with an earlier wake time, or later? What is the biological basis of this? (remember humans natural cycle length is not exactly 24 hours)
Jet lag- fatigue, irritability, and sleepiness—result form a conflict between internal clock and external zeitgebers. There is a disruption of circadian rythms and melatonin signaling by unnatural zeitgebers. The adjustment is easier to travel east to west, where you must go to bed later, but you also get to sleep in later. Jet lag is worse when phase advancing(going to an earlier time zone) because our natural Tau (rhythm length) is slightly over 24 hrs.
What is seasonal affective disorder? Why is it thought to occur and what is the therapy?
type of depression that results from insufficient amounts of daylight during the winter months.
Seasonal affective disorder is thought to be caused by overproduction of melatonin, serotonergic dysregulation, and sleep phase delays. Treatment: phototherapy (<10,000 lux), or antidepressants (SSRIs)
How many stages of sleep do humans have? What is the lightest sleep stage? The deepest?
What is the difference between REM and non‐REM (slow wave) sleep?
Sleep is characterized by rapid eye-movement(REM)beta, resembles more like you’re awake than slow wave sleep..and non-REM (nREM) sleep or slow wave sleep(SWS)
Which research technique is most often used to measure the different sleep stages in humans?
EEG recordings measure the consequences of the movement of ions across neural membranes. The movement of ions in a conducting fluid induces voltage potential shifts that can be monitored at the surface of the scalp.
Desynchronous Activity- independent action of many neurons, resembles wakefulness
Synchronous Activity- many neurons firing in unison, resembles sleep
Which sleep stage is called paradoxical sleep, because it is associated with EEG activity that resembles wakefulness?
similar to awake, EEG… heart rate and muscle tension decrease. Theta rhythm of 4-7 Hz. 4-5%. Light sleep, muscle activity slows down. Occasional muscle twitching.
Delta waves are present about half of the time. 12-15%. Very deep sleep,. Rhythmic breathing. Limited muscle activity.
rapid eye movement. Active EEG with small-amplitude, high-frequency waves, like in an awake person. 20-25%. Brain waves speed up and dreaming occurs. Muscles relax and heart rate increases—breathing is rapid and shallow.
What is the length of each sleep cycle? Do you get more slow‐wave sleep early or late in the night? What about REM?
Cycles last 90-110 minutes, but cycles early in the night have more stage 3 and 4 SWS and later cycles have more REM sleep. More slow wave sleep is usually earlier on In the night.
Dreams occur during both REM and nREM sleep. Vivid dreams occur during REM sleep: visual imagery, sense that the dreamer is “there”. Becuase of the atonia that normally accompanies REM sleep.
What are the main ‘reasons’ scientists think we sleep? Think both of rest/recovery and memories/learning.
Sleep allows synaptic plasticity leading to improved recovery. Memory formation and destruction is the only proposed explanation for sleep that justifies shutting down consciousness. To fully process info gained throughout the day, the brain must be shut down. The quality vs the quantity of sleep is what improves your memory.Restorative—metabolism, energy expenditure
What is lucid dreaming? Which brain region is responsible?
Lucid dreaming- thoughtful dreaming; the dreamer is aware that he or she is dreaming and can manipulate the experience
The prefrontal cortex must be active in order to become aware that you are dreaming. happens during more stressful dreams
What is narcolepsy? What are the symptoms and triggers? What neurotransmitter system is implicated? What is wrong in that brain system (think loss of cells...) What is responsible for the loss of cells?
Narcolepsy- a type of dyssomnia, which is an abnormality in the amount, quality, or timing of sleep. Unwanted sleep attacks. Excessive daytime sleepiness. Usually occurs following strong emotional stimulation. Do not go through SWS before REM sleep. results from disruptions in the synthesis of hypocretin. Ppl with narcolepsy have lost 90% of hypocretin neurons in the hypothalamus.
What is the difference between sleep-walking (somnambulism) and REM behavior disorder? Which sleep phase do they occur in? What other disorder is REM behavior disorder a sign of? Which neurotransmitters are involved?
Somnambulism-“sleep-walking” occurs during deepest stages of slow-wave sleep.--nREM stages They can be woken up without harm, and they are not acting out dreams.
REM Behavior Disorder-REM paralysis absent or minimized. Act out dramatic and or violent dreams. Shouting and grunting. Voluntary muscles become tonic, or tensely contracted. Up to 45% of RBD sufferers will develop Parkinson’s or Lewy Body Dementia. Norepinephrine and Domapine.
What is homeostasis? Which brain region is most important for maintaining homeostasis?
Homeostasis- physiological equilibrium. Close tolerances necessary for life—small percentage change in body temperature, electrolytes, and blood pH can cause death. Interface between internal and external environment. Endocrine system and autonomic nervous system. Controlled by the hypothalamus—which plays a major role in feeding, drinking, temperature regulation, sexual responses and determining “how you feel”
How are feedback loops between the brain and periphery related to homeostasis?
The control of body temperature involves body temperature detectors: periphery: skin, spinal chord, viscera. Central: anterior hypothalamus. There is the skin which acts as the negative feedback, and the hypothalamus acts as te device to change the variable—temperature. Also regulates hunger and satiety.
Which brainstem region is important for stimulating feeding behavior by sensing low levels of glucose in the body?
The brain uses glucose for energy. Insulin secreted from the pancreas leads to glucose storage and signals the brains…glucagon is also a hormone that leads to glucose usage. Glucoreceptors are in the nucleus of the solitary tract (NST)
Know the main hormonal signals that come from the periphery and regulate feeding and satiety—leptin and ghrelin, and whether they increase feeding or decrease feeding? Where are these hormones generated? Where in the brain do these hormones act
-Leptin-act on cells that cause increased food intake and tell to decrease food intake.—comes from fat cells. Acts with the arcuate nucleus of the hypothalamus
-Ghrelin is a neurochemical involved in initiation of eating. stimulates food intake—comes from gut stomach and pancreas.. Receptors for this have been found in the arcuate nucleus and ventromedial hypothalamus.
In the hypothalamus, there are 2 types of first order neurons involved in hunger/satiety: POMC/CART and AGRP/NPY. Which type of first order neuron increases food intake? Decreases?
AGRP/NPY increases food intake
POMC/CART decreases food intake
What is the role of hypocretin (also called orexin) in feeding (increase or decrease feeding?). How does hypocretin contribute to the rewarding properties of eating and dopamine?
How are reward responses in the brain to eating different in obese versus non-obese individuals? Think both dopamine levels and dopamine receptor levels.
Increase In the desire for weight gain promoting high calorie foods following sleep deprivation—may be due to increased hypocretin(sleep drive) leading to hunger.
Food causes less dopamine action because fewer dopamine receptors in the brain—so they need to eat more to get feelings of reward.
Since leptin is a satiety hormone, would it make a good treatment for obesity? Why or why not? What is leptin resistance?
No it would not make a good treatment because many obese people have abnormally high levels of leptin b/c lots of fatàso the body is constantly in starvation mode wanting them to eat. They need to decrease leptin resistance because no amount of leptin will lead to satiety.
Do gastric bypass and gastric banding impact body weight alone, or both body weight and metabolic health?
Gastric bypass/gastric banding impact both weight and metabolic health because they decrease leptin insensitivity.
What is anorexia? Which other mental health disorders is anorexia most closely related to?
Anorexia nervosa- maintain 85% or less of normal weight. Closely related to anxiety
Closely related to Bulimia Nervosa- cyclical pattern of binge eating and purging.
Both are thought to be caused by media images, biological factors, or addictive processes
What are hormones? How do they differ from neurotransmitters? (think site of action and distance travelled from release site) Are they made by the brain, peripheral organs or both?
Some hormones are made in the brain, and some in periphery glands. A single hormone may affect multiple tissues throughout the body, and a single body organ or process may be affected by multiple hormones.
What are the 3 main classes of hormone?
1. Protein hormones-
2. Amine hormones-
3. Steroid hormones-
consist of strings of amino acids—a short string may be referred to as a peptide hormone. ACTH, FSH, LH, TSH, GH, prolactin, insulin, glucagon, oxytocin, vasopressin.
How do the classic mechanisms of hormone action differ between protein hormones and steroid hormones (think where the receptors are located and what effects they lead to in the cell)
Protein hormone receptors- embedded in the cell membrane bind to the hormone, activating a second messenger system that affects various precesses inside the target cell.
Steroid hormones- diffuse passively in, binding to large receptor molecules in target cells. The steroid-receptor complex then binds to DNA, altering the expressing of certain genes—so called genomic effect.
Know how hormone release is stimulated, starting at the hypothalamus, pituitary, and ending at the peripheral endocrine gland (testis, ovary etc). Which site produces releasing hormones? Tropic hormones?
Electrical signals from neuroendocrine cells in hypotalamus produce an action potential lead to the secretion of hormone into the blood stream. Which are released from the axon terminals and travel via portal vein to the anterior pituitary. Then hormone producing cells in the anterior pituitary respond by releasing or inhibiting their own hormones—tropic hormones. These hormones travel through the blood stream and regulate endocrine glands throughout the body.
Sex-determining region of the Y chromosome or SRY gene, testes-determing factor protein, gonads develop into testes. Without SRY, gonads become ovaries. Then hormones from the fetal testes masculinize the body..and the brain. The fetal ovaries do not secrete androgens, so the body develops in a feminine fashion…as does the brain.
Know which sex is the ‘default’ and which results from action of SRY gene.
Male sex comes from the SRY gene, female default
How are the processes of masculinization and defeminization distinct?
During the 3rd month, male testes secrete two hormones: testosterone and anti-müllerian hormone.
Which hormone is responsible for sexual interest and behavior in males? Females? Is this an organizational or activational effect? Does more of this hormone lead to more sexual behavior?
Testosterone is the hormone responsible for the activation of sexual behavior In BOTH men and women. Ovarian hormones do not control women’s sexual activity, but may influence sexual interest. Activational effect. More does not equal better—individual differences still apply, as well as organizational effects, and other genes and experiences.
in females--promotes social monogamy. Enhances the brain reward system responses in men viewing the face of their female partner. Oxycotin and reward center: both VTA and the nucleus accumbens show greater activation to partner than unfamiliar if oxy given first.
What do females with congenital adrenal hyperplasia (CAH) tell us about the role of androgens to produce sex differences in the brain and behavior?
Females with CAH are exposed to high levels of androgens during early development…increased androgen production results in ambiguous genitalia in newborn girls. Some sexually dimorphic brain regions result from exposure to androgens in prenatal development, masculinize brain. Adrenal dysfunction leads to under production of cortisol and over production of sex steroids.
Is the sex difference in the SDN an example of an organizational or activational effect?
Due to steroid hormones active to prevent developmental apoptosis—organizational.
Are all sex differences in the brain related to reproduction? What are some other examples?
Other mechanisms that produce sex differences in the POA(pre-optic area): histone acetylation, neurogenesis(AVPV female), cell death(AVPV male, SDN female), spinogenesis/spine stabilization(male), cell survival(SDN male, AVPV female), neuronal migration(SDN male), astrocyte differentiation(male), DNA methylation.
Is there any evidence that sexual orientation may have a biological correlate in the brain and brain development? What is this evidence?
Sexual orientation- stable pattern of attraction to members of a particular sex.
oSDN is bigger in males than in females…in males that have weaker female partner preference, oSDN is smaller (intermediate between male and female size). INAH-3 is larger in men than women, and larger in straight men then gay men.
Chomsky and Pinker argue for innate ability to learn language. –no specific instructions needed to learn language, suggestive of language module.
How is language processing in the brain abnormal in schizophrenics? What about lateralization in schizophrenics when they are hearing voices?
Lateralization in scizophrenics when they hear voices=the exact same area of the brain is activated when they “hear” voices as when they hear actual sounds. They also show no hemispheric asymmetry or mirror asymmetry.There are many symptoms associated with interpretation
Is there a critical period for language acquisition? What is the evidence for it?
by 11 months infants can discriminate speech sounds from only their own language( evidence for a critical period)
Reticular formation—helps maintain desynchronized activity in cerebral cortex
Locus coerules-releases norepinephrine, active when awake and vital
Anterior raphe nuclei-releases serotonin
*both LC and ARN are most active in alert state; silent during REM*
--Muscle paralysis in REM= PONS( rostral pontine reticular formation)
-Acetylcholine: (pons, basal forebrain) high during wakefulness
-Histamine: (hypothalamus/thalamus)high during wakefulness
-Norepinephrine: (locus coeruleous) high during wakefulness
-Serotonin: (raphe nuclei) high during wakefulness