Cortex, cerebral, catecholamine

At the onset of exercise, signals from the cerebral cortex are transmitted to the vasomotor center in the medulla of the brainstem. This central command inhibits parasympathetic activity and also initiates the mass sympathetic discharge associated with exercise. Sympathetic activity (including release of catecholamines from the adrenal medulla) increases proportionally with the intensity of exercise. 

The reuptake process does not capture all of the released catecholamine. Diffusion away from the nerve terminal to distant sites can occur and has been termed volume transmission [23]. Volume transmission allows the stimulation of extrasynaptic receptors, which has been described for dopamine [24] and norepinephrine [25]. Brain regions differ in their capacity for catecholamine reuptake thus, whereas extracellular dopamine concentrations are dominated by release in the cerebral cortex, in the striatum dopamine concentrations are dominated by reuptake [26]. These regional differences in extracellular dopamine kinetics correlate with levels of dopamine transporter [27]. 

Lewis, D.A. (2001) The catecholamine innervation of primate cerebral cortex. In Solanto, M.V., Arnsten, A.F.T., and Castellanos, F.X., eds. Stimulant Drugs and ADHD Basic and Clinical Neuroscience. New York Oxford University Press, pp. 77-103. 

The three P-adrenoreceptor subtypes have varying localizations and functional properties. The brain contains both Pj and Pj receptors the density of Pj receptors varies in different brain areas to a much greater extent than does that of Pj receptors. Pj receptors predominate in the cerebral cortex Pj receptors are more common in the cerebellum. Likewise, there is a coexistence of Pj and Pj receptors in the heart, with both receptor subtypes being coupled to the electrophysiological effects of catecholamines upon the myocardium. Pj receptors tend to predominate in the lung. 

The findings obtained by Dahlstrom and Fuxe in 1964 indicated the existence of a monoaminergic innervation of the cerebral cortex without a thalamic relay, but this idea seems initially heretic. However, methodological improvements of catecholamine histofluorescence with the sensitive glyoxylic acid histochemistry (Lindvall and Bjorklund, 1974a,b), together with the development of new techniques in experimental and chemical neuroanatomy mentioned earlier (see Section 1.1) convinced the neuroscience community that transmitter-characterized subcortical systems can innervate the cerebral cortex directly. 

Gaspar P, Berger B, Febvret A, Vigny A, Henry JP (1989) Catecholamine innervation of the human cerebral cortex as revealed by comparative immunohistochemistry of tyrosine hydroxylase and dopamine-beta-hydroxylase. J Comp Neurol 279 249-271. 

Zecevic N, Verney C (1995) Development of the catecholamine neurons in human embryos and fetuses, with special emphasis on the innervation of the cerebral cortex. J Comp Neurol 357 509-535. 

Cyclic AMP accumulation by catecholamines is generally associated with /3-adrenoceptor stimulation, but there is recent evidence that a adrenoceptor stimulation also can lead to cyclic AMP accumulation. For example, in slices of rat cerebral cortex, the effect of isoprenaline on the cyclic AMP level was inhibited by a /3-adrenoceptor blocking drug and yet inhibition of the effect of noradrenaline required the combination of a P and an a-adrenoceptor blocking drug [65,66]. 

The stimulation of both the endocrine and metabolic response has been the subject of much study. There is little doubt that nervous transmission both from injured peripheral parts and the cerebral cortex are important initiators. Apprehension and fear can cause the increased secretion of not only catecholamines, but also cortisol and aldosterone. 

Jimenez Del Rio, M.J. Pinxteren, J. De Potter, W.P. Ebinger, G. and Vauquelin, G. Serotonin-binding proteins in the bovine cerebral cortex Interactions with serotonin and catecholamines. Eur J Pharmacol 225 225-234, 1992. 

Synthesis of prostaglandins (PGE2 and PGF2 ) and their release into cerebral ventricular fluid have been reported to occur in mammalian central nervous system tissue. Levels of prostaglandins tend to range from 0.1 to 2.5 pg/g tissue. Their presence has been reported in cerebral cortex, cerebellum, and hippocampus, and levels can be enhanced in the presence of norepinephrine and other catecholamines. Thromboxane synthesis has also been reported to occur. The trace amounts of prostacyclin are probably the result of contamination of brain preparations with vascular elements. 

The cause of ADHD is unknown. It is possible that there is loss of inhibitory control in the limbic system because of a disorder in the right frontal cerebral cortex. Dopamine D4 receptors are implicated in ADHD and there is a catecholamine hypothesis of a deficit of... 

Although it has long been anticipated that factors analagous to those described in the PNS are also important in the differentiation of neurons in the central nervous system (CNS), only in the last year have molecules with this designated role been identified. Studies from this laboratory have indicated the existence of important differentiation factors for the CNS in a number of tissue extracts. This line of research originated with the observation that muscle and its constituents could dramatically alter the differentiative course of certain brain neurons. Thus, when neurons from the cerebral cortex, which do not normally manufacture catecholamine (CA) neurotransmitters, were grown in co-culture with heart, skeletal muscle. 

Scopolamine-induced locomotor activities and rotational behaviour in mice were depressed by catecholamines. The effect of topical scopolamine on the cerebral cortex showed epileptic manifestations in non-anaesthetized cats, and acoustically evoked cortical potentials were decreased. ... 

The outside layer(s) of a gland or a special tissue, in contrast to the inner layers or medulla. For example, the adrenal cortex secretes steroid hormones whereas, the adrenal medulla secretes catecholamine hormones (adrenaline and noradrenaline). However, the most important cortex is the cerebral cortex, which is the outer layer or thinking part of the human brain. 

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