Hippocampi

Kageyama and Wong-Riley (1982) showed that cytochrome oxidase staining in the somata of CA3 pyramidal cells and various interneurons was more intense than in CAl pyramidal and dentate granule cells, while very low levels of cytochrome oxidase activity was observed in the stratum lucidum of CA3. 

Haloperidol, a dopamine receptor antagonist, was cytotoxic to mouse clonal hippocampal HT22 cells in a concentration-dependent manner and caused death by oxidative stress as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazo-lium bromide (Post et al. 1998). The addition of haloperidol to HT22 cells led to an increase in intracellular peroxides and a rime-dependent drop in the intracellular glutathione levels. Haloperidol-induced oxidative cell death was prevented by melatonin, its precursor N-acetyl serotonin, and most effectively by a-tocopherol. 

Nitric oxide synthase III inununoreactivity was observed in the dendrites of hippocampal pyramidal cells of knockout and wild type animals indicating that even in functional NOS-III knockouts the non-deleted N-terminal trunk of the protein is still expressed (Zanger et al. 1999). NOS-III immuno-reactivity for the C-terminal portion of the protein was found in wild types only. Electron microscopically NOS-III immunoreactivity was not located at synapses but was present in and associated with mitochondria which were mainly located in dendrites compared to the soma and were never seen in axons. 

Perforant pathway stimulation resulted in an increase in the number of nNOS-immunoreactive neurones in the stratum radiatum of the CAl and CA3 subfields of the rat hippocampus proper, and the hilus and the dentate gyrus (Lumme et al. 2000). The morphology and distribution of the nNOS im-munoreactive neurones resembled that of interneurones. 

LiCl (12 mEq/kg i.p.) and tacrine (5mg/kg i.p.) enhanced the expression of nNOS, but not eNOS, enzyme protein in the rat hippocampus during the preconvulsive period and this triggered seizures and hippocampal damage (Bagetta etal. 2002). Systemic administration of 7-nitro indazole (50 mg/ kg given i.p. 30 min before tacrine), a selective inhi- 

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Thyroid hormone receptors (THRs) are subdivided intoa and P types, each having two isoforms. In rat brain, THR, mRNA is present in hippocampus, hypothalmus, cortex, cerebellum, and amygdala. Thyroxine (l-T (284) and triiodothyronine (l-T ) (285) are endogenous ligands for the THRs. TRIAC (286) is a THR antagonist. Selective ligands for PPARs have yet to be identified (Table 16). 

The effects of VIP and PACAP are mediated by three GPCR subtypes, VIP, VIP2, and PACAP receptor, coupled to the activation of adenjiate cyclase (54). The VIP subtype is localized ia the lung, Hver, and iatestiae, and the cortex, hippocampus, and olfactory bulb ia the CNS. The VIP2 receptor is most abundant ia the CNS, ia particular ia the thalamus, hippocampus, hypothalamus, and suprachiasmatic nucleus. PACAP receptors have a wide distribution ia the CNS with highest levels ia the olfactory bulb, the dentate gyms, and the cerebellum (84). The receptor is also present ia the pituitary. The VIP and PACAP receptors have been cloned. 

AVP is excitatory in the ventral hippocampus, either directly or by potentiation of glutamatergic responses. An inhibitory effect has been observed in AVP may be involved in the formation of long-term potentiation and thus learning and memory. However, AVP is proconvulsive, may augment the formation of dmg tolerance and dependence, and affects cardiovascular regulatory processes. 

BDNF (brain-derived neurotrophic factor) is a neuro-trophin, i.e. a target-derived growth factor, which is expressed in the brain predominantly in the hippocampus. It acts through its tyrosine kinase receptor, trkB,... 

Traumatic brain injury is the most common cause of death in subjects under the age of 40, and an important risk factor for AD. Loss of hippocampal cells and depletion of ACh and of muscarinic receptors can be attenuated in injured experimental animals, improve blood perfusion in ischemic areas and increase cholinergic transmission in cortex and hippocampus the same mechanism invoked for treatment of VD. 

Similar to C1C-5, C1C-3 is present in endosomes. It is also found in synaptic vesicles. In both instances, and similar to C1C-5, it is necessary for the efficient intravesicular acidification. The acidification of synaptic vesicles is particularly important as their uptake of neurotransmitters depends on the electrochemical proton gradient. Surprisingly, the disruption of C1C-3 in mice resulted in a drastic degeneration of the hippocampus and the retina. Much less is known about C1C-4, which, however, also appears to be present in endosomal compartments. 

Dronabinol (tetrahydrocannabinol), the active principle from cannabis and synthetic cannabinoids, nabilone and levonantradol are effective in treating nausea and vomiting in cancer chemotherapy. The mode of action is unclear but appears to involve cannabinoid CBi receptors. Cannabinoids have been shown to reduce acetylcholine release in the cortex and hippocampus, and have been suggested to inhibit medullary activity by a cortical action. Inhibition of prostaglandin synthesis and release of endorphins may also be involved in the antiemetic effect. A review of trials of dronabinol, nabilone or levonantradol concluded that while the cannabinoids were superior to placebo or dopamine receptor antagonists in controlling emesis... 

Alzheimer s disease (AD) 2. In the hippocampus of p-amylo id-treated rats, an animal model of AD, 2-AG levels are elevated and exert neuroprotection but also participate in memory retention loss 2. Inhibitors of cellular re-uptake or CB-, antagonists, possibly depending on the phase of the disorder... 

Neuronal excitotoxicity AEA levels are elevated in the hippocampus of mice treated with kainic acid. 2-AG levels are elevated in rats treated with pilocarpine These are two animal models of epileptic seizures, where the endocannabinoids play an anti-convulsant and protective function Inhibitors of cellular re-uptake... 

Ferreira VM, Frausto S, Browning MD et al (2001) Ionotropic glutamate receptor subunit expression in the rat hippocampus lack of an effect of a long-term ethanol exposure paradigm. Alcohol Clin Exp Res 25 1536-1541... 

The hippocampus, which got its name from the Greek word for seahorse, due to its form, is a nucleus in the depth of the temporal lobe. The hippocampus is important for the integration of sensory information, for spatial orientation and for memory formation. The hippocampal formation contains the CA (cornu ammonis) regions, the dentate gyms and the subiculum. 

Hi-receptors in the adrenal medulla stimulates the release of the two catecholamines noradrenaline and adrenaline as well as enkephalins. In the heart, histamine produces negative inotropic effects via Hr receptor stimulation, but these are normally masked by the positive effects of H2-receptor stimulation on heart rate and force of contraction. Histamine Hi-receptors are widely distributed in human brain and highest densities are found in neocortex, hippocampus, nucleus accumbens, thalamus and posterior hypothalamus where they predominantly excite neuronal activity. Histamine Hrreceptor stimulation can also activate peripheral sensory nerve endings leading to itching and a surrounding vasodilatation ( flare ) due to an axonal reflex and the consequent release of peptide neurotransmitters from collateral nerve endings. 

Collection of interconnected subcortical and cortical brain structures (including hypothalamus, amygdala, and hippocampus) integrating multimodal intero- and exteroceptive information to produce coherent neuroendocrine and behavioral output, and to support memory functions. 

GLT1/EAAT2 (SLC1A2) Astrocytes in cerebral cortex, hippocampus 5-100 Clearance of interstitial glutamate... 

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