Published: Jan. 1, 2016
Cholesterol is an important constituent of cell membranes and plays a crucial role in the compartmentalization of the plasma membrane and signaling. Brain cholesterol accounts for a large proportion of the body’s total cholesterol, existing in two pools: the plasma membranes of neurons and glial cells and the myelin membranes . Cholesterol has been recently shown to be important for synaptic transmission, and a link between cholesterol metabolism defects and neurodegenerative disorders is now recognized. Many neurodegenerative diseases are characterized by impaired cholesterol turnover in the brain. However, at which stage the cholesterol biosynthetic pathway is perturbed and how this …
Published: May 31, 2014
The mesolimbic dopamine system is believed to be a key component in the processing of rewarding information by the brain, although the precise nature of dopamine release remains unknown. Avoidance conditioning combines reward (positive) and aversion (negative) phenomena. Here the activity of 60 neurons in the ventral tegmental area (VTA) was studied in freely moving rabbits during the acquisition and performance of an active avoidance. A total of 48 % of the recorded neurons responded to the conditioned stimulus (CS). A significant predominance of excitatory responses to the (CS) was demonstrated. Two main patterns of cell responses to the CS …