Effects of D-Ala2-Met5-enkephalinamide microinjections placed into the bed nucleus of the stria terminalis upon affective defense behavior in the cat.

This study examined the effects of intracerebral injections of D-Ala2-Met5-enkephalinamide (DAME) upon hypothalamically elicited hissing behavior in the cat. The bed nucleus of the stria terminalis (BNST) was selected for investigation because of its anatomical connections with the medial hypothalamus, its relatively high concentrations of enkephalins and opiate receptors and its demonstrated ability to modulate hypothalamically elicited aggressive reactions in the cat. DAME microinjected into the BNST in 1.0 or 10.0 micrograms/0.5 microliter quantities resulted in significant dose dependent increases in mean latencies for elicitation of the hissing response. Suppression of hissing following the 1.0 microgram dose of DAME was selectively diminished by prior administration of naloxone. These findings suggest that the opiate receptors within the BNST play a role in the regulation of the hissing component of hypothalamically elicited affective defense behavior.