Attacks of anxiety, panic and frenzy, and their related depression: a hypothesis.

The hypothesis is that the pathogenesis of attacks of anxiety, panic or frenzy (hyperactive disorders) rests on the abnormal activation of the same brain-controlled survival mechanism, and that the subsequent depression is part of this nosological continuum. The acute activation phase would be the counterpart of two principal types of reaction to threat and imminent attack: run-for-life or fight-for-life, sub-served by brain-controlled metabolic activation to make energy available for either. The phase of depression that follows would represent the recovery phase during which homeostatic controls and metabolism, distorted during the acute attacks, are restored to normal.

Developmental asymmetries in experimental animals.

The early embryo orients to the antero-posterior axis and differentiates along this, and the dorso-ventral and lateral axes. From Drosophila melanogaster, detailed knowledge has accrued of how segmentation and dorso-ventral differentiation proceed, and of their genic control, mostly by selector and homeobox (Hox) genes. The study of the control of lateral differentiation, instead, has been largely neglected.