The Mammalian Diving Response: Inroads to Its Neural Control

Abstract

The mammalian diving response (DR) is a remarkable behavior that was first formally studied by Laurence Irving and Per Scholander in the late 1930s. The DR is called such because it is most prominent in marine mammals such as seals, whales, and dolphins, but nevertheless is found in all mammals studied. It consists generally of breathing cessation (apnea), a dramatic slowing of heart rate (bradycardia), and an increase in peripheral vasoconstriction. The DR is thought to conserve vital oxygen stores and thus maintain life by directing perfusion to the two organs most essential for life-the heart and the brain. The DR is important, not only for its dramatic power over autonomic function, but also because it alters normal homeostatic reflexes such as the baroreceptor reflex and respiratory chemoreceptor reflex. The neurons driving the reflex circuits for the DR are contained within the medulla and spinal cord since the response remains after the brainstem transection at the pontomedullary junction. Neuroanatomical and physiological data suggesting brainstem areas important for the apnea, bradycardia, and peripheral vasoconstriction induced by underwater submersion are reviewed. Defining the brainstem circuit for the DR may open broad avenues for understanding the mechanisms of suprabulbar control of autonomic function in general, as well as implicate its role in some clinical states. Knowledge of the proposed diving circuit should facilitate studies on elite human divers performing breath-holding dives as well as investigations on sudden infant death syndrome (SIDS), stroke, migraine headache, and arrhythmias. We have speculated that the DR is the most powerful autonomic reflex known.

Trigeminal Nerve Control of Cerebral Blood Flow: A Brief Review

“…The maxillary division innervates the skin over the midface and upper lip and maintains projection to the medullary dorsal horn and RVLM (Panneton and Gan, 2020). Though few papers have addressed the role of the maxillary division of the trigeminal nerve in altering CBF (Li et al, 2019(Li et al, , 2021, previous research has demonstrated clinical utility of V2 stimulation in the setting of epilepsy (DeGiorgio et al, 2003(DeGiorgio et al, , 2006(DeGiorgio et al, , 2009Pop et al, 2011;Gil-López et al, 2020).…”

Assessment of respiratory effort with EMG extracted from ECG recordings during prolonged breath holds: Insights into obstructive apnea and extreme physiology

“…The absence of breathing during the quiet easy phase of the breath hold is not due to a voluntary suppression of the central respiratory rhythm, but a voluntary suppression of respiratory motor behavior (Parkes, 2006). The easy phase can be extended when the apnea is accompanied by a powerful dive response that conserves and prioritizes oxygen-rich blood to the central organs (brain and heart) (Panneton, 2013;Panneton & Gan, 2020). In this respect it may be comparable to the unconscious/involuntary apnea seen in association with seizure activity that occurs together with modest bradycardia, an open airway, and no involuntary breathing movements (Lacuey et al, 2017;Mooney et al, 2019;Nakase et al, 2016).…”

Can the mammalian dive response override posttraumatic stress disorder?

“…It is important to note that activation of the sympathetic and parasympathetic nervous systems at the same time could result in what is known as autonomic conflict, and can produce cardiac arrhythmias [20]. While these arrhythmias are generally benign, participants should be screened for any conditions that might lead to complications, such as water phobias, breath holding phobias, claustrophobia, heart disease, and cardiac rhythm abnormalities.…”

“…The mammalian dive response (MDR) is also a well-documented evolutionary adaptation that is shared by all vertebrates [19] and mammals [20] studied to date. When the human face is submerged in water and apneic, receptors in the nostrils and on the face elicit biological responses to conserve oxygen [19][20][21][22].…”

“…The mammalian dive response (MDR) is also a well-documented evolutionary adaptation that is shared by all vertebrates [19] and mammals [20] studied to date. When the human face is submerged in water and apneic, receptors in the nostrils and on the face elicit biological responses to conserve oxygen [19][20][21][22]. These responses consist of parasympathetically mediated bradycardia (slowing of the heart rate), vasoconstriction, and the redirection of blood flow to the brain and core [19][20][21][22].…”