has 12 functionally segregated nuclei groups of soma one of them is laterla geniculate nucleus (LGN) tract from LGN to primare visual cortex, thalamal cortical tract.
potential energy of neuron at rest
70 mV (Na+, K+, Cl-) movement of ions thru channels sets up energy to expel stuff
what happens when you eat a puffer fish?
tetrodotoxin, plugs sodium channels neuron will not function
explain life of neurotransmitter
synthesized in cell body (over 200 kinds) transported down axon from soma in microtubules deposited at the end into synaptic vesicles in axon terminal
space between axon terminal and dendrite (SMALL)
excitatory post synaptic response (dopamine, glutamate)
inhibitory post synaptic response (GABA)
what can happen to neurotransmitters when they are expelled?
reuptake- taken back up to presynaptic side enzymatic degredation go to receptor
selectively inhibits reuptake of seratonin so more works (prozac)
seratonin is monoamine monoamine oxydase breaks down seratonin (MAO) MAOI inhibits enymatic degredation (parnate)
deep black in midbrain rich dopamine producer if it goes away--> parkinsons treatable with L Dopa, precursor to dopamine dopamine beta hydroxilase converts to dopamine, levels restored too much dopamine, hallucinate & go psycho (cocaine)
firing of neuron all or none refractory period
absolute refractory period
1 ms will not go at all
relative refractory period
4 ms can go with overstimluation
neurons communicate with:
other neurons, muscle (acetylcholine) enzyme ACHase stops firing to muscle
VX nerve gas
destroys ACHase. muscles cannot relax, die.
Olds & Milner experiment
1957, electrode touching "brain reward pathway" (ventral tegmental area) rat presses a bar positive response: increas probability will choose stimulation over food/water