A couple of paths from the hypothalamus release histamine, thereby:
a. increasing arousal.
b. initiating sleep.
c. shifting sleep from REM to NREM.
d. slowing the circadian rhythm.
Prior to the work of Santiago Ramon y Cajal, what did many investigators believe?
a. Nerves conducted impulses at the speed of light.
b. Transmission across a synapse was just as fast as transmission along an axon.
c. The tip of an axon physically merged with the next neuron.
d. All neurons were of similar size and shape.
Depolarization is to ____ as hyperpolarization is to ____.
a. excitation; inhibition
b. inhibition; excitation
c. increasing the threshold; decreasing the threshold