PSY397H5 Chapter Notes - Chapter 3: Habituation, Covalent Bond, Cellular Compartment
Document Summary
Acquisition of memory is a graded phenomenon. After sensitizing stimulation, the animal exhibits a more robust, longer- lasting gill withdrawal in response to identical light touch or water squirt; The gtp bound version of the g protein is active and interacts with second-messenger generating enzymes (or ion channels in some cases), greatly increasing their catalytic rate and producing elevations of intracellular levels of the second messengers; The net effect of g protein involvement is both amplification and prolongation of the neurotransmitter-stimulated event; Long term synaptic facilitation in aplysia involves changes in gene expression and resulting anatomical changes. Sensitization of aplysia to the defensive withdrawal reflex is mediated by an increase in the number of synaptic contacts between siphon sensory neurons and follower motor neurons; Thereby stimulation of the siphon sensory neuron elicits a greater response in gill withdrawal, because a greater number and density of excitatory connections are made between the two cells;
