The Chemical Life in the Brain



A synapse is the contact and transmission zone of informations among neurons, in other words a synapse is the way neurons communicate with each other. 

The Neurotransmitters


The neurotransmitters are molecules released by a pre-synaptic neuron. They activate receptors on another neuron called post-synaptic.

6 Important Neurotransmitters

Acetylcholine (Ach) 

The Ach is involved in many physiological functions and control movements. When it comes to memory, acetylcholine plays a major role; indeed, in case of memory loss due to age and Alhzeimer, Ah production decreases.  

 Dopamine (DA)

Dopamine is involved in : exploration behavior, in the search of pleasure, the escape or the fight of vigilance. The DA is also a very important element when it comes to muscle movements. With the Parkinson's disease, for example, which can be described by a considerable reduction in the ability to perform movements , it is observed that there is severe deficit of dopamine. However, if there is a high concentration of dopamine, schizophrenia symptoms are observed.

 Noradrenaline (NA) 

The NA is very important when it comes to brain function. This neurotransmitter is involved in the processes of the following: attention, awakening, memory, anxiety, pain and humor. Frenquently used to cure depression, since it improves temper. 



Serotonine (5-ht)

Serotonine plays a major role when it comes to regulating temper along with other emotional, alimentary and sexual behaviors. This chemical messenger is also involved in sleep and aggressiveness. 

The GABA favors calmness and relaxation by reducing muscle tone, it is also involved in vision. A weak GABA can lead to coma, while a high concentration of that neurotransmitter can cause epilepsy.


Adrenaline is generally produced following a stress. It prepares the body to flee or to fight: there is an increase in pulse, blood pressure, muscle strength along with muscle capacity.

Autonomic Nervous System 

These neurotransmitters are involved in the autonomic nervous system. The ANS regulates automatic physiological functions 

Ces neurotransmetteurs sont impliqués dans le système nerveux autonome. Le SNA régule les fonctions physiologiques automatiques de l'organisme dans le but de maintenir l'homéostasie, soit l'équilibre du corps. Il est indépendant de notre volonté. 

Il a 2 composantes antagonistes : le SNA parasympathique et le SNA sympathique 

Références : 

Texte : Bear, M.F., Connors, B.W. et Paradiso, M.A. (2016). Neurosciences à la découverte du cerveau (4ièmeed.; traduit et adapté par André Nieoullon). Paris, France :  Éditions Pradel. ;;; 

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