Neurons and their morphologies

Neurons (or nerve cells), fundamental units of the brain and nervous system, have different types and morphologies. Neurons are the basis of the functioning of the brain. They are surrounded by non-neuronal cells calledglial cells . The different parts of neurons Neurons are made up of three parts. A  cell body , also called soma (from the Greek somâ meaning […]

White matter

White matter is the part of the tissue of the central nervous system (including the brain and spinal cord) that mainly contains extensions of neurons. These extensions called axons are surrounded by a myelin sheath which is the origin of this whitish structure, as well as glial cells which nourish and protect the nerve cells. […]

The limbic system

The limbic system is one of the oldest parts of the brain. It is present in humans, but also in reptiles and fish. A term introduced by Paul MacLean in 1952, the limbic system was long considered the seat of emotions (aggressiveness, fear, pleasure, anger), representing the dialogue between the brain and the body.  Functions of the limbic system […]

Cortical areas and their functions

Cortical areas are areas of the brain located in the cerebral cortex. The cerebral cortex refers to the superficial part of the brain and containing the gray matter of the cerebral hemispheres. The experiments of electrical stimulation and ablation of the cortex made it possible to: map the cerebral cortex. This mapping was updated thanks to the technique […]

The hippocampus and its role in the brain

The hippocampus is a structure of the brain that plays a fundamental role in learning and memory. It is damaged in Alzheimer’s disease. Knowing about the hippocampus has helped researchers understand how memory works. Location The hippocampus is a structure of the brain that is part of the temporal lobe of the cerebral cortex. The name comes from the Greek […]

Basal ganglia

The  basal ganglia are areas of the brain located below the cortex, deep in both hemispheres of the brain . These nuclei are involved in the control of voluntary motor movements, learning and decision-making on the performance of motor activities. Diseases that affect this region include Parkinson’s disease  and Huntington’s disease. They are surrounded by white matter from the cerebral hemisphere. Divisions of […]

What are the cranial nerves?

The 12 cranial nerves form a set of nerves that originate in the brain. Their functions are sensory, motor or both at the same time: Cranial sensory nerves help a person see, smell, and hear. Cranial motor nerves help control muscle movement in the head and neck. Each nerve has a name that reflects its […]

The nervous impulse

The neuron is different from the other cells in its capacity to generate an electric signal that is called a nervous impulse. These signals – known as action potentials – are transmitted from one neuron to another and ensure the functional activity of the brain. How are these signals transmitted? Neurons are separated from their […]

Amyloid: a protein involved in Alzheimer’s?

Amyloid is a soluble protein that is normally eliminated in healthy people. In people with Alzheimer’s, this protein becomes insoluble and agglutinates outside neurons to form amyloid (or senile) plaques (30 to 100 microns in diameter). This accumulation affects certain parts of the brain. Beta-amyloid comes from a larger protein found in the membrane surrounding healthy […]

Brain atrophy

Brain atrophy is a reduction of the size of the brain. It is due to a loss of neurons or a loss of the number of connections (synapses) between brain cells.  People who suffer from brain atrophy usually develop cognitive impairment as a result of brain damage, particular in areas associated wth memory. There are two main types […]