A neuron (/ˈnjʊərɒn/ nyewr-on or /ˈnʊərɒn/ newr-on; also known as a neurone or nerve cell) is an electrically excitable cell that processes and transmits information through electrical and chemical signals. These signals between neurons occur via synapses, specialized connections with other cells. Neurons can connect to each other to form neural networks. Neurons are the core components of the brain and spinal cord of the central nervous system (CNS), and of the ganglia of the peripheral nervous system (PNS). Specialized types of neurons include: sensory neurons which respond to touch, sound, light and all other stimuli affecting the cells of the sensory organs that then send signals to the spinal cord and brain, motor neurons that receive signals from the brain and spinal cord to cause muscle contractions and affect glandular outputs, and interneurons which connect neurons to other neurons within the same region of the brain, or spinal cord in neural networks.

A typical neuron consists of a cell body (soma), dendrites, and an axon. The term neurite is used to describe either a dendrite or an axon, particularly in its undifferentiated stage. Dendrites are thin structures that arise from the cell body, often extending for hundreds of micrometres and branching multiple times, giving rise to a complex “dendritic tree”. An axon is a special cellular extension that arises from the cell body at a site called the axon hillock and travels for a distance, as far as 1 meter in humans or even more in other species. The cell body of a neuron frequently gives rise to multiple dendrites, but never to more than one axon, although the axon may branch hundreds of times before it terminates. At the majority of synapses, signals are sent from the axon of one neuron to a dendrite of another. There are, however, many exceptions to these rules: neurons that lack dendrites, neurons that have no axon, synapses that connect an axon to another axon or a dendrite to another dendrite, etc.

Hyperthermic Conditioning Helps You Build a Better Brain in a Number of Different Ways including the Following:

A. Hyperthermic conditioning results in increased levels of prolactin: Prolactin is important for the promotion of myelin growth (which helps the brain function faster and repair nerve cell damage). Studies have compared the prolactin responses of subjects reaching exhaustion via cycling to subjects heated to the same core temperature passively. It was found that with both forms of heating the prolactin response was the same. The conclusion is that core temperature is the key stimulus for prolactin release.

B. Hyperthermic conditioning results in increased endorphin levels: Brain chemicals known as neurotransmitters include “endorphins”, which function to transmit electrical signals within the nervous system. At least 20 types of endorphins have been demonstrated in humans. Endorphins can be found in the pituitary gland and in other parts of the brain, or distributed throughout the nervous system. Stress and discomfort (pain)  are the two most common factors leading to the release of endorphins. Endorphins interact with the opiate receptors in the brain to reduce perception of pain (and act similarly to drugs such as morphine and codeine). In addition to decreased feelings of pain, secretion of endorphins leads to feelings of euphoria, modulation of appetite, release of sex hormones, and enhancement of the immune response. The so-called “runner’s high” can result from a boost in endorphin levels, and the sense of well-being associated with intensive endurance athletics. Thermal conditioning and ATE also boost endorphin levels. The boost in endorphin levels associated with running is believed to be related to heat stress. Animal studies have found that heat stress from thermal exposure can significantly increase endorphin levels.

C. Hyperthermic conditioning results in increased heat shock protein* (HSP) production: When injury occurs to a part of the brain, such as stroke or traumatic injury, HSP production is often increased to repair damage

D. Hyperthermic conditioning results in increased brain-derived neurotrophic factor (BDNF): Research has established that exercise triggers the production of BDNF, which helps support the growth (and survival) of existing brain cells and the development of new ones (certain types of exercise have been shown to triple the synthesis of BDNF in the human brain)!  BDNF is a protein or “neuropeptide”- a member of the neurotrophin family of growth factors—known to
be important for long-term memory. As humans age, BDNF levels typically fall. This decline is one of the main reasons brain function generally deteriorates in the elderly. Research has shown that exercise can help to counteract these age-related drops in BDNF and can restore young levels of BDNF in the aging brain. BDNF activates brain stem cells to produce new neurons and triggers other important chemicals. Increased neurogenesis is believed to enhance learning, long-term memory and cognitive function as well as ameliorate anxiety, depression, schizophrenia, epilepsy, Alzheimer’s disease, drug addiction, obesity and other conditions.(46)  A recent study with 15 subjects showed increased levels of serum BDNF from baseline of 13% and 30% with cycle ergometer exercise. Another study with 11 subjects showed increased levels of serum BDNF which were enhanced with exercise in the heat. It was shown that heat stress increased the expression of BDNF more than exercise alone. Since permeability of the blood–brain barrier increases with exercise in the heat, the opinion of the researchers was that thermal exercise causes a higher cerebral output of BDNF.

E. Hyperthermic conditioning results in increased perfusion and size of hippocampus:  The hippopcampus generally shrinks in late adulthood, resulting in impaired memory and increased risk of dementia. A study with 120 older adults without dementia showed that exercise intervention increases cerebral blood volume and perfusion and the size of hippocampus.

F. Hyperthermic conditioning results in improved cognitive processes and memory: Increased cerebral blood flow and oxygenation, in addition to increased levels of serum BDNF as shown above, can improve cognitive processes and memory. Studies have shown that both hyperthermic conditioning  and exercise improve cognition and brain performance, including memory.

G. Hyperthermic conditioning results in increased production of norepinephrine: Studies have shown that active thermal exercise and hyperthermic conditioning increase norepinephrine by as much as 310% and 86% (Norepinephrine helps improve focus and attention to detail.
APL (American Performance Labs) is a research group dedicated to the collection, analysis, and dissemination of published research and articles on the science of hyperthermia and the various applications, technologies and protocols for the use of hyperthermic conditioning.