Behavioral Neuroscience Summers

Turtle Eyeblink Behavior Sensory Stimulation of Eyeblink Eyeblink Motor Output Neuromuscular Function In vitro Conditioning

text:Kandel pages 1243 & 849 Glu ACh BDNF Turtles and Ecology Eyeblink Circuitry end     Acronyms/Abbreviations     Syllabus

Eyeblink Conditioning
III. Turtle Afferent Eyeblink Pathway  		

	A. Sensory mechano-receptors in Cornea and Face
	
		1. depolarized by air puff
		
	B. Afferent signals along trigeminal nerve (cranial nerve V)
	
		1. largest cranial nerve
		
			a. 3 divisions: opthalmic, maxillary, mandibular
			
			b. sensory and motor components
			
		2. sensory somata in trigeminal ganglion
		
	C. to terminal fieds the ipsilateral principle sensory trigeminal nucleus (pV)
				
		2. also to the ipsilateral principle abduscens motor nucleus (pVI)
		
			a. monosynaptic eyeblink reflex
		
		3. and to the ipsilateral accessory abduscens motor nucleus (accVI)
		
			a. also monosynaptic pathway in Varanid lizards
		
		4. and to cerebellum
	
	D. Trigeminal afferent sensory neurons are glutamatergic
	
		1. Glu binding to NMDA and AMPA receptors in synapses of abduscens
		    motor neurons
			
			a. synapses found on soma and proximal dendrites of abduscens
			    motor neurons
			
			b. NMDA and AMPA mediate different temporal components of 
			    abduscens motor output
				
				i. R1 = early: monosynaptic path
				    reinforced by disynaptic path
				
				ii. R2 = later: polysynaptic path including 
				     medulla and cerebellum
		
	E. Disynaptic pathway
	
		1. Sensory afferents to rostral trigeminal nuclear complex
		
		2. Interneurons of trigeminal nuclei to abducens (accVI and pVI)
		    motor nuclei
			
			a. separate interneuron systems to principle (pVI) 
			    and accessory (accVI) motor nuclei