Defensive Treading Behavior Analysis
Objective: Measurement of fearful defensive treading behavior elicited by muscimol microinjection in caudal nucleus accumbens shell, and assessment of bivalent rostrocaudal gradients for GABA-elicited motivated and affective behaviors
Protocol Steps
Rostral shell muscimol microinjection
Microinject muscimol into the rostral medial accumbens shell
Note: Farthest rostral injections at 75 ng dose
View evidence from paper
“Microinjection of the GABA A agonist muscimol in the rostral medial accumbens shell in rats elicits appetitive eating behavior”
Caudal shell muscimol microinjection
Microinject muscimol into the caudal nucleus accumbens shell
Note: Elicits fearful defensive treading behavior
View evidence from paper
“in the caudal shell instead elicits fearful defensive treading behavior”
Measure eating behavior
Quantify appetitive eating behavior following microinjection
Note: Increased eating observed with rostral injections
View evidence from paper
“Farthest rostral muscimol microinjections (75 ng) caused increased eating behavior”
Measure defensive treading behavior
Quantify fearful defensive treading behavior following microinjection
Note: Negative defensive treading observed with caudal injections
View evidence from paper
“caudal shell microinjections elicited negative defensive treading”
Conditioned place preference/avoidance testing
Measure behavioral place preference or avoidance conditioning in response to microinjection effects
Note: Rostral injections produce positive place preferences; caudal injections produce place avoidance
View evidence from paper
“measured behavioral place preference/avoidance conditioning and affective hedonic and aversive orofacial expressions”
Measure taste-elicited orofacial expressions
Quantify hedonic and aversive orofacial expressions (gapes, etc.) in response to taste stimuli
Note: Includes measurement of liking and disliking reactions
View evidence from paper
“affective hedonic and aversive orofacial expressions of taste-elicited "liking" and "disliking" (gapes, etc.)”
Sucrose taste reaction assessment
Present sucrose and measure positive hedonic reactions or negative aversive reactions
Note: Rostral injections increase positive reactions; caudal injections increase negative reactions
View evidence from paper
“increased positive hedonic reactions to the taste of sucrose”
Quinine taste reaction assessment
Present quinine and measure aversive taste reactions
Note: Used to assess negative taste reactions
View evidence from paper
“negative aversive reactions to sucrose or quinine tastes”
Intermediate site microinjection
Microinject muscimol into intermediate rostral nucleus accumbens shell sites
Note: Produces mixed positive/negative valence effects
View evidence from paper
“Intermediate rostral microinjections elicited effects of mixed positive/negative valence”