Cerebral cortex functions

Riera JJ, Schousboe A, Waagepetersen HS, Howarth C, Hyder F. 2008. The micro-architecture of the cerebral cortex Functional neuroimaging models and metabolism. 

The class II cytokine receptor family includes receptors for interferon a/P (lEN a/P) and y (lENy) and IL-10. lEN-y immunoreactivity has been found in neurons in the hypothalamus, cerebral cortex, mammilary nuclei, and dorsal tegmentum. Astrocytes and microglia in vitro can be stimulated to express class II histocompatibiHty complex (MHC-II) antigens by lEN-y, which may be involved in the presentation of antigen to T-ceUs by astrocytes. Thus lEN-y may be critical in CNS-immune function and dysfunction especially in regard to neuronal and gHal apoptotic processes. 

High concentrations of KOP have been found in the cerebral cortex and hypothalamus KOP is also present in the gastrointestinal tract, in immune cells as well as in other peripheral tissues. KOPs have been implicated in the regulation of nociception, diuresis, feeding, neuroendocrine and immune system functions [2]. 

It is generally felt that a substance is more likely to be a NT if it is unevenly distributed in the CNS although if it is widely used it will be widely distributed. Certainly the high concentration (5-10 pmol/g) of dopamine, compared with that of any other monoamine in the striatum or with dopamine in other brain areas, was indicative of its subsequently established role as a NT in that part of the CNS. This does not mean it cannot have an important function in other areas such as the mesolimbic system and parts of the cerebral cortex where it is present in much lower concentrations. In fact the concentration of the monoamines outside the striatum is very much lower than that of the amino acids but since the amino acids may have important biochemical functions that necessitate their widespread distribution, the NT component of any given level of amino acid is difficult to establish. 

McCormick, DA, Pape, HC and Williamson, A (1991) Actions of norepinephrine in the cerebral cortex and thalamus implications for function of the central noradrenergic system. Prog. Brain Res. 88 293-305. 

In that and subsequent studies (Kosofsky 1985 Blue et al. 1988a), a distinct laminar pattern of innervation was found in somatosensory cortex, and a quite different pattern in the cingulate cortex, hippocampus, and dentate gyrus, where there are distinct bands of highly varicose axons. In the primate, the 5-HT innervation of cerebral cortex is denser and more highly differentiated among different architectonic and functional areas (Kosofsky et al. 1984 Morrison et al. 1982 Morrison and Foote 1986 Wilson and Molliver 1986 Wilson et al. 1989). For example, marked differences in the density and distribution of 5-HT axons are found in the macaque on either side of the central sulcus, in primary motor and somatosensory cortex while... 

Describe the activity of each of the functional areas of the cerebral cortex... 

The gray matter, which contains the cell bodies of neurons, is on the outer surface of the cerebrum and forms the cerebral cortex. The white matter, composed of the myelinated axons of neurons, is found underlying the cortex in the core of the cerebrum. These axons are bundled together according to function and organized into units referred to as tracts. The three types of tracts in the cerebrum are ... 

The cerebral cortex is organized into several functionally discrete areas (see Figure 6.4). However, it is important to remember that no single area functions in isolation. The activity in each area depends on neurons in other areas for incoming and outgoing messages. 

Saper, C.B., Iversen, S., and Frackowiak, R., Integration of sensory and motor function the association areas of the cerebral cortex and the cognitive capabilities of the brain, in Principles of Neuroscience, 4th ed., Kandel, E.R., Schwartz, J.H., and Jessell, T.M., Eds., McGraw-Hill, New York, 2000, chap. 19. 

All ascending tracts cross to the opposite side of the CNS. For example, sensory input entering the left side of the spinal cord ultimately terminates on the right side of the cerebral cortex. These tracts may cross — at the level of entry into the spinal cord a few segments above the level of entry or within the medulla of the brainstem. The locations of specific ascending tracts are illustrated in Figure 7.2 and a summary of their functions is found in Table 7.1. 

Signals are also transmitted to the reticular formation of the brainstem by way of the spinoreticular tract. The reticular formation plays an important role in the response to pain. First, it facilitates avoidance reflexes at all levels of the spinal cord and, second, it is responsible for the significant arousal effects of pain. Signals from the reticular formation cause an increase in the electrical activity of the cerebral cortex associated with increased alertness. Furthermore, it sends nerve impulses to the hypothalamus to influence its functions associated with sudden alertness, such as increased heart rate and... 

The cell bodies of third-order sensory neurons are located in the thalamus. These neurons transmit the pain signal to the somatosensory cortex. The function of this region of the brain is to localize and perceive the intensity of the painful stimulus. Further transmission of the signal to the association areas of the cerebral cortex is important for the perception and meaningfulness of the painful stimulus. 

McCormick, D. A. (1993). Actions of acetylcholine in the cerebral cortex and thalamus and implications for function. Prog. Brain. Res. 98, 303-8. 

The basal forebrain is an important way station in the activation of the cerebral cortex from the reticular activating system. AMPA and NMDA injections into the basal forebrain increase wakefulness and reduce sleep (Cape Jones, 2000 Manfridi et al, 1999), effects that are blocked by AMPA and NMDA receptor antagonists (Manfridi et al, 1999). The excitatory cortical projections of the basal forebrain have long been considered purely cholinergic, but many basal forebrain neurons that project to the cortex are now known to contain Glu, which may function as a co-transmitter or even as the primary excitatory neurotransmitter (Manns et al, 2001). The basal forebrain also affects vigilance via synapses to HCT cells in the lateral hypothalamus some of these synapses are glutamatergic (Henny Jones, 2006). 

Textbooks on neuroscience often describe the location and function of hundreds of individual brain regions (see references above). However, for current purposes these will be kept to a minimum (Figure 2.1). Anatomically, the brain can be subdivided into the forebrain containing the telencephalon and diencephalon, the midbrain or mesencephalon and the hindbrain (metencephalon and myelencephalon). The telencephalon includes the left and right cerebral hemispheres encompassed by the cerebral cortex (neocortex). Cortex is a translation of the word bark and is so-called because its surface, made up of numerous sulci (grooves or invaginations) and gyri (raised areas), is on the outer surface of the brain like the bark of a tree. Each hemisphere is divided into four lobes, named from the front (rostral) to back (caudal) of the brain frontal, temporal, parietal and occipital. 

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