Brain Mechanisms

Action-inhibiting system (AIS) vs. submission system. I believe that the work of Adams is very interesting; I agree with the majority of the facts he joins together and, broadly speaking, with his general model for the neural circuitry that triggers offense, defense. and submission. Indeed, his model and my own published work have many points of similarity (see Laborit 1975. p 578).

I have named what he calls the "submission system" the "action-inhibiting system" (AIS), and I have distinguished it, as he has, from the fight and flight system. But I think that this system is also distinct from the "conservation withdrawal" system, which little rodents and some human babies are able to use (Engel and Smale 1972).

Although Adams mentions the importance of memory, and of the animal's prior experience, for the functioning of this circuitry, I believe that this factor is not sufficiently emphasized. We have shown experimentally that the AIS is triggered by the memory of the inescapability of punishment, or, in others words, by the memory of the impossibility of coping with a previously experienced situation. The animal's response is not innate, in our opinion, but learned (Kunz, Valette, and Laborit 1974).

I regret, too, that the role of endocrine regulation in the behavior was not discussed (see Laborit 1976). It is possible to differentiate the systemic response to electrical stimulation of dorsomedial and basolateral amygdala, as well as that of dorsal and basal hippocampus (Laborit and Baron 1977; and Laborit, Baron, and Laurent 1977). The effect of hydrocortisone on AIS activity and of adrenocorticotrophic hormone on the action-activating system (periventricular system and medial forebrain bundle) is also very interesting,

In the same way, some results of experiments involving intracerebroventricular administration of neuromediatory substances (dopamine, norepinephrine, muscarinic or nicotinic antagonists or agonists, and serotonin synthesis inhibitors or precursors) casts some light on the relations between neuroendocrine systems and behavior.

Perhaps the most fundamental criticism that will be made of this work concerns the basic approach to the problems exclusively by way of the stimulus-response concept. In particular, in our opinion, "motivation" arises from an internal drive, a homeostatic perturbation [see Toates "Homeostasis and Drinking" BBS 2(1) 1979]. External stimuli in particular give rise to imprinting, or, later, the encoding of pleasure, discomfort, or pain, which trigger reinforcement or inhibition. Therefore, learning processes use the innate final common neural circuitry of action or inhibition to control behavior (Laborit 1975-1978). But, aside from this light criticism, which only expresses my opinion, the Adams paper is a very full report and will be useful for every research worker in this field.