Behavioral Neuroscience, lecture on Aplysia and its behavior
USD Department of Biology
Behavioral Neuroscience
Summers
Aplysia Behavior
Sensory Stimulation of Siphon Withdrawl
Motor Output driving Siphon Withdrawal
Gating
Conditioning & Memory
Aplysia Siphon and Gill text:Kandel pages 1248-1257
Glu
Acetylcholine (ACh)
5-HT
Aplysia and Siphon Withdrawl
Siphon Withdrawl Circuitry
end     Acronyms/Abbreviations     Syllabus
Siphon Withdrawal
V. Motor output driving Siphon Withdrawal 		

	A. Siphon-gill withdrawal reflex Motor neurons
	
		1. 13 Cell bodies in abdominal ganglion
		
		2. terminals: siphon or gill
		
			a. excitatory
			
				i. Acetylcholine (ACh)
				
				ii. bind Nicotinic-like receptors
				
					(1) just like vertebrate motor junctions
				
		3. stimulates retraction of gill and siphon within mantle
		
	B. Tail-siphon reflex motor neurons
	
		1. 3 somata each left and right pedal ganglia
		
		2. terminals in tail
		
			a. excitatory
			
				i. Acetylcholine (ACh)
				
		3. stimulates defensive retraction of tail
		
		4. siphon retraction requires interneuron activity
		
			a. somata of motor neurons in abdominal ganglion
			
				i. just like siphon-gill retraction

	
	C. Adaptive modification of the reflexes requires Gating
	
		1. via interneurons
		
		2. to match the behavioral response to the level of threat
	
	
	D. Sensory + Interneuron synaptic potentials summate
	
		1. temporally and spatially
		
		2. motor cells discharge repeatedly
		
		3. results in strong reflexive withdrawal of gill/siphon/tail

V.V ACh

VI. Gating