Behavioral Neuroscience Summers

Sexual Behavior Reflexes Sensory Reception - Tactile Receptors Spinal Synapses Afferent Spinal Pathways

Hypothalamic Gating Efferent Motor Cascade Neuromuscular Production of Lordosis Integrated Story of Lordosis VIP Substance P Estrogens

5-HT GnRH ACh Lordosis figures   Sensory Receptors Spinal Cord   Lordosis Circuitry end     Acronyms/Abbreviations

LORDOSIS
XII.  Motor Cascade along the Efferent Circuitry

	A. Efferent circuitry delivers motor commands to the neuromuscular junctions
	
	
		1. An Integrated signal that includes:
		
		
			a. arousal
			
			
			b. gating
				
				i. hormonal and neuromodulatory potentiation
				
				
			c. reflex
			

	B. Arousal


		1. midbrain reticular formation

			a. reflexive arousal
		
			b. activates medullary reticular neurons
			

	C. Input from gating

		1. effernt signal only extant when VMN is active
		
			a. requires priming from E2
			
				i. and disinhibition by P
							
					(1) blocks inhibitory effect of 5-HT
					
				ii. hormonal
	
			b. neuromodulator potentiation from limbic brain


		2. midbrain central gray

			a. input from VMN stimulates lordosis 

				i. activates medullary reticular neurons
				
			b. input from POA inhibits lordosis
			
			c. MCG to medullary reticular neurons stimulates 
			   motor neurons


	D. Reflex can now be completed via medullary reticular formation 

		1. midbrain reticular formation (reflexive arousal) +
	       midbrain central gray (hormonal + neuromodulator potentiation)
	       neurons activate medullary reticular neurons

		2. project through reticulospinal tract to ventral horn motor neurons


	E. Efferent spinal neurons stimulate contraction of back muscles

		1. behavior facilitated by postural adjustments
		    stimulated by LVN neurons

			a. synergism between reticulospinal and vestibulospinal
			   neurons