Gluco- and Mineralocorticoid Receptors Essay

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Gluco- and mineralocorticoid receptors
GCs bind to intracellular receptors, as they can diffuse through the plasma membrane, as seen in figure 2. GC and MC receptors(GR and MR) can form homodimers and heterodimers or remain as monomers, allowing them to pass on various kinds of signals. Monomers can interact with transcription factors and repress stress responses such as peptide synthesis (such as CRH and vasopressin), blocking stress responses going on. This is not always the case though, as GR dimers can cause increases in CRH in extrahypothalamic areas. Cortocosteroid receptor function interacts with neurotransmitter and neuropeptide function and stress responsiveness is memorized and maintained in the case of something similar
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GCs increase blood pressure, heart rate and metabolism by impacting many enzyme pathways through GC receptors and following enzyme induction, linking stress to hypertension.(Sapolsky et al, 2000. Besides the previously discussed effects of GCs on the body, they also influence the brain. The central nervous system houses many GC receptors and mineralocorticoid (MC) receptors; GC receptors have a low affinity for GCs relative to MC receptors(Lucassen et al, 2014). Expression of GC receptors differs; receptor density is the highest in the PVN and in limbic neurons modulating the PVN. MC receptors are also abundantly expressed on limbic neurons. Co-expression of both these receptors is found in the hippocampus, dentate gyrus, amygdala and many cortical areas (De Kloet et al, 2005).

Effect of GCs on the brain
Many known GR targets are enzymes for growth factors, neuropeptides and cell adhesion factors. Because of this, stressors can induce changes in neurons; in brain areas such as the hippocampus en dentate gyrus dendrite structure and size, alongside neurogenesis are regulated by occupation of MC receptors by GCs. The MC receptor activation restrains proliferation and cell death in the dentate gyrus; brief stress periods suppress proliferation and increase cell death (de Kloet et al, 2005). Long-term potentiation is also impacted by GCs; they seem to impact learning so that it is easier to

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