Hypothalamic mechanisms for sexual, aggressive, and other motivational behaviors in the opossum, Didelphis virginiana.

Abstract

MALE MATING BEHAVIOR, BITING ATTACK, DEFENSIVE THREAT, EATING, GROOMING, YAWNING, INVESTIGATING, AND ESCAPE-LIKE ACTIVITY WERE PRODUCED BY ELECTRICAL STIMULATION OF DIFFERENTIATED ZONES IN THE HYPOTHALAMUS AND PREOPTIC AREA OF OPOSSUMS. CLOSE ANATOMICAL CORRESPONDENCE WITH SIMILAR MECHANISMS IN HIGHER SPECIES SUGGESTED CONSIDERABLE PHYLOGENETIC CONTINUITY FROM EARLY MAMMALIAN LEVELS. RESPONSES INVOLVING ENVIRONMENTAL GOALS WERE NOT PERFORMED WITHOUT THE OBJECTS, INDICATING THAT THEY WERE FACILITATED RATHER THAN DIRECTLY ELICITED BY THE STIMULATION. THE INTERELECTRODE VARIABILITY IN THE COMPLETENESS OF COMPLEX RESPONSE PATTERNS SUGGESTED THAT EACH ZONE SENDS DIVERGENT FACILITATORY OUTPUT TO SEPARATE SENSORIMOTOR MECHANISMS FOR DIFFERENT RESPONSE ELEMENTS. THE PERFORMANCE OF THE MATING PATTERN WITHOUT INTROMISSION WAS AN EFFECTIVE REWARD IN A MAZE. (28 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)