>>Brain Depression
INTRODUCTION
Depression, which is often referred to as the "common cold" of mental illness, is not just the "down in the dumps" or the "black" feeling that everyone experiences from time to time. It is more serious and affects a person's mind and body. Depression of the brain involves chemicals called neurotransmitters, which assist in transmitting messages between nerve cells in the brain. Some of these neurotransmitters, which regulate mood, when not available in sufficient quantities, may result in depression. The depressive state of mind has been associated to a particular part of the brain called the limbic system. This is the area of the brain that regulates activities such as emotions, physical and sexual drives, and the stress response. Of prime importance(in association to depression), in the limbic system, are the hypothalamus, the hippocampus and the amygdala sections that are associated with emotional reaction. The neurotransmitters norepinephrine, dopamine, and serotonin seem to be particularly important in depression.
* The hippocampus is responsible for many functions, besides being associated with short-term declarative memory. It is part of the limbic system and stores information related to emotions(emotional information), coming from the senses via the amygdala.
* The neurotransmitters like serotonin and norepinephrine help transfer messages throughout structures of the brain's nerve cells. These nerve cells, called neurons do not actually touch one another. Instead, they are separated by a small gap called the synapse or the synaptic gap through which the messages pass.
* Neurotransmitters like serotonin, after they pass throgh the synapse are received into certain sites called receptors. From there, they are either converted into electrical impulses and transmitted or they may be taken back in by the neuron that originally released it. The latter case is called reuptake. The reuptake of serotonin results in depletion in the levels of serotonin in the synaptic gap leading to depression.
>> Endocrine System and Depression
HORMONAL CHANGES..
* The endocrine glands which are responsible for producing and releasing hormones also have a role to play in depression. Hormonal changes, like those occuring during menstrual cycles and pregnancy in women, which alter levels of estrogen and progesterone, also causes depression.