Behavioral Neuroscience, lecture on Lordosis Behavior
USD Department of Biology
Behavioral Neuroscience
Sexual Behavior
Sensory Reception - Tactile Receptors
Spinal Synapses
Ruffini Endings Afferent Spinal Pathways Hypothalamic Gating
Efferent Motor Cascade
Neuromuscular Production of Lordosis
Integrated Story of Lordosis
Substance P
Lordosis figures
Sensory Receptors
Spinal Cord
Lordosis Circuitry
end     Acronyms/Abbreviations
III. Sensory Reception - Afferent Circuitry 			
!First Neural Circuit for a Mammalian Behaivor!

	A. Tactile Receptors
		1. male's body against female's rump region
			a. or sensory inspection
		2. Ruffini endings
			a. slowly adapting: to a barrage of impulses
				i. sub-cutaneous mechanoreceptive units with soma in
				   dorsal root ganglia
			b. respond to sustained pressure stimulation
				i. most primary sensory neurons respond
				ii. only pressure units and type I (hair + pressure) units
				    have sustained responses to lordosis-triggering
					(1) specialized sensory response
						(a) Ruffini end organs
							(i) run parallel to skin
                            (ii) also found in finger tips
                            (iii) respond to slippage, chage of angle, thermoreception
					(2) spatial summation across pressure units
						facilitates reflex				

			c. E2 stimulates increased Ruffini receptors

				i. expanded receptive field of pudendal nerve

					(1) broader 
			d. mating/repeated mating can increase receptivity
				i. increased LQ
				ii. requires intromission - vaginal, cervical stimulation
		3. Sensory fibers to spinal cord
			a. from skin of rump, tail base and perineum
				i. via the dorsal roots at L5, L6 and S1
				ii. pudendal nerve
			b. from flanks
				i. via L1 and L2
			c. cell bodies in dorsal root ganglia

			d. the terminals are deep in the dorsal horn
			   of the spinal cord

				i. units responding only to pressure
				   found primarily in the intermediate gray

				ii. Units responding to movement of hair located
				    more dorsally in the dorsal horn

				iii. Units responding to subdermal stimulation
				     usually found at greater depths

			e. transmitters of these neurons are colocalized peptides 
				i. inhibited by another peptide


V. Substance P

VI. Spinal Synapses