Fight or flight and the hypothalamus

Abstract

The "fight or flight" response (hereafter referred to as “this response”) is a universal behavioral response of all vertebrates and is evolutionarily well conserved. When the acute stress response (stress defense response) is triggered, the defense area of the hypothalamus becomes a command post that simultaneously switches on this response. The molecular mechanism involved in this response is as follows. Orexin, produced by the lateral hypothalamus, is the substance responsible for simultaneous activation of the circulatory and respiratory systems and analgesia. Osteocalcin, a protein that makes up 25% of bone, induces an acute stress response. Mitochondrial calcium single transporters in the mitochondrial inner membrane are responsible for transporting calcium ions, and are involved in increased heart rate. Neural circuits in the habenula-nucleus accumbens control behavioral choices in this response. The multidimensional control mechanism of the hypothalamus is assumed to consist of a very simple two-pole system: the emergency type and the normal type. The control mode of the stress response can be represented by a two-dimensional portfolio consisting of two intersecting axes: the neural information transfer system control axis and the heat energy system control axis. This response might reflect a pattern of emergency-type hypothalamic activity with extreme sympathetic dominance and extreme thermal energy expenditure dominance. ATP receptors are widely expressed in the hypothalamus and likely involve purinergic neurotransmission in the hypothalamus in this response. Stress intolerance is a condition in which endurance to stress is not demonstrated to the expected level, resulting in poor physical health.