SHLOMO YEHUDA

Bar Ilan University, Department of Psychology, Psychopharmacology Laboratory,
52900, Ramat Gan, Israel

Abstract

In addition to a gradual loss of neurons in various brain regions, major biochemical changes in the aging brain affect the neuronal membrane that is the “site of action” for many essential functions learning and memory, sleep, pain threshold, and thermoregulation. Normal physiological functioning includes the transmission of axonal information, regulation of membrane-bound enzymes, control of ionic channels and various receptors. All are highly dependent on membrane fluidity, where rigidity is increased during aging. The significantly higher level of cholesterol in aging neuronal membrane, the slow rate of cholesterol turnover, and the decreased level of total PUFA may result from poor passage rate via the blood-brain barrier, or from a decreased rate of incomrporation into the membrane. Administration of a ratio of 1:4 of omega 3/omega 6 PUFA may improve the neuronal membrane functions and behavior of the aging brain.

INTRODUCTION

Brain aging is a complex process involving many factors. Some are independent and others are inter-related. The aging brain is associated with many biochemical, physiological and behavioral deficiencies including, learning and memory loss, sleep disturbance, pain threshold alteration, and disturbed thermoregulation.
To better understand the aging process, the structural approach has been proposed, in which major structural changes occurring during this period are studied, e.g., the gradual loss of neurons in various brain regions. However, the course of the progression of these changes has not yet been established. While we know that it is a long and slow process, we do not know the appropriate statistic model to best predict the rate or form of the decline in either structure or function. The ability of the brain to create new synapses (synaptic genesis) is diminished during this period for reasons that are not understood. Concurrently, there are major biochemical changes in the brain that affect the neuronal membrane that is the “site of action” for many essential functions. Such functions include the conductio ...