Updated Review-17

The ultimate testing of the model needs recording from single neurons of relevant neural structures during naturally-elicited behaviors. Although this has been done in the midbrain central gray during defense, it needs to be done in the anterior hypothalamus during offense, and then in the hypothetical mechanisms for sensory analyzers and motor patterning generators under natural conditions. Once neurons of motivational mechanisms can be recorded, it should be possible to identify these neurons in anesthetized animals and determine if their inputs and outputs correspond to those presented in the model.

It will be especially useful to investigate the neural mechanisms of naturally-elicited offense in the cat, as well as in muroid rodents.

The technical difficulty of single neuron recording with microelectrodes during naturally-occurring behavior has limited its use. Perhaps less direct methods to record neural activity such as the c-Fos and deoxyglucose measures and local application or blocking of neurotransmitters can achieve these goals. To do so, however, will demand more exacting experimental design that distinguishes clearly, not only between offense and defense, but additionally between competitive and territorial offense and anti-predator and consociate defense. Furthermore, to investigate the various motor patterns of aggressive behavior, it is necessary to provide and monitor the releasing and directing stimuli that are required under natural conditons for the expression of many motor patterns.

Insofar as electrical and chemical stimulation are used, it will be important to control for the possibility that multiple systems are stimulated simultaneously. This is an even greater problem for systemic pharmacological interventions.

If the assumption is correct that the neural mechanisms of aggressive behavior are relatively simple in structure and change little during the course of evolution, then it may be assumed that further research, even if it rejects the model presented here, will permit the development of a new model that accurately describes the brain mechanisms of agonistic behavior.