Card Set Information
Neuroscience Exam 1
Most wide-spread excitatory transmitter in the CNS
Funciotn on the motor end plate, neuromuscular synapse, and also a major NT in the CNS.
In motoneurons between the pre- and post-synaptic
Found in NT, CV system, also in CNS
When released at heart, increase heart rate and force of contraction, costrict blood vessels
Neurotransmitter: alpha-aminobutyric acid(GABA)
Widespread inhibitory transmitter in CNS
Why do stroke patients become rigid?
Damage to the inhibitory neurons so activity goes up
Normally, there is a balance/SUM between inhibitory and excitatory
Repetitive firing of a single presynaptic cell.
Summing the effect on AP
Typical way to allow pre-synapse to affect the post-synaptic membrane
Concentration of NT goes up
AP goes down multiple pre-synptic neurons so the 2 AP will have affect on the post-synsptic membrane.
Added in space
Response is greater than either AP alone
Result--post-synaptic membrane can depolarize
need to be added in space. If one arrives earlier than will not depolarize enough to reach threshold
Where the fast soidium channels are located
Get end plate potentials to summate to get propagation of AP to peripheral.
Even if membrane is partially depolarizes, if on post-synaptic membrane and not the initial segment, does NOT matter.
NEED THE FAST SODIUM CHANNELS
How does Cl
inhibit without being hyperpolarized?
Excitationn when Cl
channels are open.
now if activation of inhibitory synapses causes a large number of Cl
channels to open, so that T
Calculate new membrane potential that must consider
opening of the Na+ and K+ channels will not cause as much depolarization, as shown by the transference equation:
Now have to split the transferences to 0.25 because all transferences must equal 1
= (0.25)(-90 mV) +(0.25)(60 mV) + (0.5)(-85 mV) =