Purkinje cell cortex

Spinocerebellar Cerebellar cortex (Purkinje cells), 6-39 40-81 Ataxin-1 NI (n, c)... 

CYP8A1 in neurons of bovine, rat and human brain, especially Purkinje cells of cerebellum and cortical neurons, but not glial cells by IHC (Mehl et al., 1999). CYP8A1 mRNA and protein in blood vessels of human brain, pyramidal cells of cortex and hippocampus, and Purkinje cells of cerebellum (Siegle et al., 2000). 0.000161 per GAPDH mRNA in whole adult human brain by RT-RT-PCR (Nishimura et al., 2003). 

IHC shows ethanol induction of CYP2E1 in olfactory bulbs, frontal cortex, hippocampus, and cerebellum of male rats nicotine induces in olfactory bulbs, frontal cortex, olfactory tubercle, cerebellum, and brainstem. More CYP2E1 found in brains from human alcoholics and alcoholic smokers in granular cells of the dentate gyrus, pyramidal cells of CA2 and CA3 hippocampus, and cerebellar Purkinje cells. More CYP2E1 In frontal cortices of alcoholic smokers versus all nonsmokers. CYP2E1 in cultured human neuroblastoma cells Induced by nicotine (Howard et al., 2003). 

Chronic nicotine induces CYP2E1 expression in cortical pyramidal neurons and cerebellar Purkinje cells no change seen in temporal cortex, hippocampus, putamen, or thalamus of monkey brain (Joshi and Tyndale, 2005, 2006). 

Cerebral cortex (layer I-VI, selected interneurons and principal cells) hippocampus (selected interneurons and principal cells) pallidum striatum (interneurons) thalamic relay nuclei olfactory bulb (mitral cells and interneurons) cerebellum (Purkinje cells and granule cells) deep cerebellar nuclei amygdala basal forebrain substantia nigra pars reticulata inferior colliculus brainstem... 

At the same time that the motor neurons send signals to the muscles, branches travel into other parts of the brain including the olivary nuclei, which send neurons into the cerebellum. The cerebellum acts as a kind of computer needed for fine tuning of the impulses to the muscles. Injury to the cerebellum leads to difficulty in finely coordinated motions. Input to the Purkinje cells arises from the climbing fibers, which originate in the inferior olive of the brain stem. Each climbing fiber activates a single Purkinje cell, but the dendrites of each Purkinje cell also form as many as 200,000 different synapses with parallel fibers that run across the cortex of the cerebellum (Fig. 30-15). 

The parallel fibers receive input from many sources via a complex series of mossy fibers and granule cells and influence the firing of the Punkinje cells. The output from the Purkinje cells is entirely inhibitory. It is transmitted via synapses in the cerebellar nuclei to neurons that lead back to the cerebral cortex, into the thalamus, and down the spinal cord.411 The pathway to the cortex completes an inhibitory feedback loop, of which there are many in the nervous system. For details see Llinas404 and Nicholls.149... 

Cerebellar degeneration, degeneration of the cerebellar cortex, especially the Purkinje cells, causing ataxia and truncal instability. 

Ito M, Kano M (1982) Long-lasting depression of parallel fiber-Purkinje cell transmission induced by conjunctive stimulation of parallel fibers and climbing fibers in the cerebellar cortex. Neu-rosci Lett 33 253-8... 

In the human brain, the highest expression levels of h5-HT1B receptor mRNA are located in the caudate and putamen. Expression is also observed in layer V of the cortex, in Purkinje cells of the cerebellum. h5-HT1B and h5-HT1D receptor mRNAs are found in neurons within the human dorsal raphe nucleus. 

Acute cerebral ischemia affects neurons first and the more resistant glia and blood vessels in later stages. Deep cortical layers such as layer III of the cerebral cortex are especially vulnerable, mainly in the parietal and occipital regions and less in the frontal and temporal areas. The more vulnerable neurons are those of the caudate and putamen, the pyramidal cells of Sommer s area and the Purkinje cells in the cerebellum. The thalamus and brainstem are more resistant to hypoxia and ischemia. White matter is generally considered to be more resistant than grey matter. 

Fig. 16.10a-d. A 66-year-old man found comatose after severe intoxication. The neuropathological findings show diffuse cortical necrosis (recent, a) the arrows indicate that edema predominates in the depth of the sulci. There are shrunken neurons with eosinophilic cytoplasm and pyknotic nuclei (b, c). The cerebellar cortex shows shrunken necrotic Purkinje cells (d)... 

The pathological hallmark of PCD with Yo antibodies is degeneration and loss of Purkinje cells and often of granule cells as well. CD8+ cells are found in the cerebellum and sometimes in the cerebral cortex, and there is diffuse microglial activation [72]. In some cases, there are changes in the corticospinal and spinocerebellar tracts and dorsal columns [42]. 

Ikai et al. (1992) reported that the VTA sends projections to the rat cerebellar cortex and deep cerebellar nuclei bilaterally, with a slight contralateral predominance. In this study, dopaminergic efferents of the A10 cell group were reported to reach mainly the granule cell layer of the cerebellar cortex in the lateral portion of the hemispheres, with additional input to the Purkinje cell layer, but sparing the molecular layer. The deep cerebellar nuclei, and in particular the lateral nucleus, were instead found to receive inputs from nondopaminergic cells of the VTA, reciprocating projections to the VTA bilaterally and with a contralateral predominance. 

In the monkey cerebellar cortex, Melchitzky and Lewis (2000) have recently described a dopaminergic innervation that matched the rat data in terms of laminar distribution (reaching mainly the granule cell layer and arborizing densely in the subjacent Purkinje cell layer), but was confined to certain lobules of the cerebellar vermis. 

This disease is a late onset disorder of the cerebellum characterized by selective and progressive loss of Purkinje cells. Initially the disease was thought to be confined to the cerebellar cortex, dentate nucleus, and inferior olives, but more recent studies suggest more widespread cerebellar involvement (Seidel et al., 2009 Wang et al.,... 

Purkinje cell—single layer of large cell bodies in the cerebellar cortex, between the molecular (left) and granular (right) layers. 

---