Brain regions limbic system

How and in what regions of the brain does morphine act In 1979, scientists discovered that there are specific receptor sites for morphine and other opiates and that these sites are clustered in the brain s limbic system, the area involved in emotion and the perception of pain. Scientists then asked, "Why does the human brain have receptor sites specific for morphine " Could it be that the brain produces its own opiates In 1974, scientists discovered that opiate-like compounds are indeed present in the brain in 1975, they isolated a brain opiate that was named enkephalin, meaning "in the brain." Unlike morphine and its derivatives, enkephalin possesses an entirely different... 

Figure 8.1 The pain pathway. The pain signal is transmitted to several regions of the brain, including the thalamus reticular formation hypothalamus limbic system and somatosensory cortex. Each region carries out a specific aspect of the response to pain.

Nerve signals from the thalamus and the reticular formation are transmitted to the limbic system as well as the hypothalamus. Together, these regions of the brain are responsible for behavioral and emotional responses to pain. The limbic system, in particular, may be involved with the mood-altering and attention-narrowing effect of pain. 

GR 38032F had no significant effects on brain levels of DA or 5-HT or their oxidative metabolites in various brain regions in rats [111]. However, this compound selectively antagonized DA metabolism in rats with activated meso-limbic system. 

In the brain, methamphetamine causes massive amounts of the neurotransmitters dopamine, norepinephrine, and serotonin to be released from neurons in the brain, particularly in the limbic system and frontal cortex. Scientists believe the increased dopamine release in these brain regions is responsible for methamphetamine s ability to keep people awake, alert, energetic, active, and possibly addicted. Methamphetamine acts on a variety of brain regions to produce a number of different effects (Table 2.1). 

Another problem in validating targets for behavioral disorders related to neurotransmitter abnormalities is the interplay between several neurotransmitter systems in specific brain regions. For example, in the hippocampus, limbic, and nigral-striatal areas, functions connected by serotonin, norepinephrine, and dopamine are interconnected so that blocking selected receptor subtypes or changing synaptic levels of certain neurotransmitters may... 

From this brief description, it is apparent that the brain is really an assembly of organs all of which are structurally and functionally interconnected. Undoubtedly one of the most important areas for the psychopharmacologist is the so-called limbic system which is concerned with emotion. This region consists of the hippocampus (concerned with memory... 

Limbic system—Brain regions involved in controlling emotions. 

From the receptor cells nerves pass through the olfactory lobes at the front end of the brain direct to the central basal region, the part known as the "limbic system." This forms part of our deep-seated unconscious mind, being associated with the control of emotion and sexual activity, as well as with feelings of pleasure. In evolutionary terms it is also the oldest part of the brain, providing evidence of the early and continuing importance of the sense of smell in animal behavior. 

Other structures in this area make up the limbic system which is directly linked to the olfactory system. Areas called the septal nuclei and amygdala contain regions often called the pleasure centres, with the hippocampus concerned with motivational memory. Projections from the cerebral cortex connect with the thalamus, hypothalamus and posterior pituitary gland. The network of connections between all these different areas of the brain is highly complex. The role of the limbic system is significant in autonomic (involuntary or non-conscious) reactions that are implicated with emotional responses including fear, rage and motivation. 

Through the pathways of the mesolimbic system (a term introduced by Ungerstedt in 1971), the basal ganglia provide an interface with limbic brain regions. This interface has been repeatedly implicated in psychiatric diseases, such as schizophrenia and other affective disorders, as well as in reward and addiction. 

---