Brain complexity: surprise: males and females differ (Introduction)

by David Turell , Friday, September 04, 2015, 01:40 (3150 days ago) @ David Turell

Inhibitory chemicals are different:-http://www.sciencedaily.com/releases/2015/08/150812135651.htm-"Many brain disorders vary between the sexes, but how biology and culture contribute to these differences has been unclear. Now Northwestern neuroscientists have found an intrinsic biological difference between males and females in the molecular regulation of synapses in the hippocampus. This provides a scientific reason to believe that female and male brains may respond differently to drugs targeting certain synaptic pathways.-***-"Among their findings, the scientists found that a drug called URB-597, which regulates a molecule important in neurotransmitter release, had an effect in females that it did not have in males. While the study was done in rats, it has broad implications for humans because this drug and others like it are currently being tested in clinical trials in humans.-***-"Specifically, Woolley and her research team found that in female brains the drug URB-597 increased the inhibitory effect of a key endocannabinoid in the brain, called anandamide, causing a decrease in the release of neurotransmitters. In male brains, the drug had no effect. (The difference is not related to circulating reproductive hormones.)-***-"The subject of many clinical trials, endocannabinoids are molecules that help regulate the amount of certain neurotransmitters released at synapses, the gap between neurons. These molecules are involved in a variety of physiological processes including memory, motivational state, appetite and pain as well as in epilepsy, a neurological disorder. (Their name comes from the fact that endocannabinoids activate the same neural receptors as the active ingredient in marijuana.)-***-"For 20 years, Woolley actively avoided studying sex differences in the brain until her own data showed her that differences between females and males were real. Her discovery, reported in 2012, that estrogens decreased inhibitory synaptic transmission in the brains of female rats but not in males, changed her thinking.-***-"Building on these earlier findings, Woolley and her team used a series of electrophysiological and biochemical studies to pinpoint what causes this effect. The researchers found the difference between males and females lies in the interaction between the molecules ERalpha and mGluR1. Details of the molecular pathway are reported in the new study."-Take away: Connections in computers are fixed, variable in the brain.