Organization of brainstem behavioral systems

Area of Science:

• Neuroscience
• Behavioral Biology

Background:

• Traditional views often underestimate the brainstem's role in complex behaviors.
• Recent literature suggests a more fundamental contribution of the brainstem.

Purpose of the Study:

• To review evidence implicating the brainstem in the elaboration of adaptive behaviors.
• To re-evaluate the role of brainstem networks in behavior integration.

Main Methods:

• Literature review of studies on decerebrate animals.
• Analysis of findings from electrical stimulation of brainstem areas.
• Examination of neuroanatomical and behavioral data.

Main Results:

• Decerebrate animals display a substantial behavioral repertoire.
• Electrical stimulation of the brainstem elicits complex, coordinated behaviors (e.g., eating, grooming, attack).
• Caudal brainstem networks show goal specificity and stimulus control in behavior, and are implicated in reward/aversion.

Conclusions:

• Integrating mechanisms for species-characteristic behaviors are intrinsic to the brainstem.
• Rostral hypothalamic-limbic mechanisms may represent phylogenetically newer controls, refining but not originating these behaviors.