Kisspeptin signaling via the kisspeptin receptor G-protein-coupled receptor-54 plays a fundamental role in the onset of puberty and the regulation of mammalian reproduction. In this immunocytochemical study we addressed the (i) topography, (ii) sexual dimorphism, (iii) relationship to gonadotropin-releasing hormone (GnRH) neurons and (iv) neurokinin B content of kisspeptin-immunoreactive hypothalamic neurons in human autopsy samples. In females, kisspeptin-immunoreactive axons formed a dense periventricular plexus and profusely innervated capillary vessels in the infundibular stalk. Most immunolabeled somata occurred in the infundibular nucleus. Many cells were also embedded in the periventricular fiber plexus. Rostrally, they formed a prominent periventricular cell mass (magnocellular paraventricular nucleus). Robust sex differences were noticed in that fibers and somata were significantly less numerous in male individuals. In dual-immunolabeled specimens, fine kisspeptin-immunoreactive axon varicosities formed axo-somatic, axo-dendritic and axo-axonal contacts with GnRH neurons. Dual-immunofluorescent studies established that 77% of kisspeptin-immunoreactive cells in the infundibular nucleus synthesize the tachykinin peptide neurokinin B, which is known to play crucial role in human fertility; 56 and 17% of kisspeptin fibers in the infundibular and periventricular nuclei, respectively, contained neurokinin B immunoreactivity. Site-specific co-localization patterns implied that kisspeptin neurons in the infundibular nucleus and elsewhere contributed differentially to these plexuses. This study describes the distribution and robust sexual dimorphism of kisspeptin-immunoreactive elements in human hypothalami, reveals neuronal contacts between kisspeptin-immunoreactive fibers and GnRH cells, and demonstrates co-synthesis of kisspeptins and neurokinin B in the infundibular nucleus. The neuroanatomical information will contribute to our understanding of central mechanisms whereby kisspeptins regulate human fertility.

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Compelling evidence now exists for estrogen's involvement in the regulation of mood and cognitive functions. Serum estrogen levels have been shown to play an important role in the expression of psychiatric disorders such as depression and schizophrenia. We have characterized the distribution of the estrogen receptors, ERalpha and ERbeta, in the human brain and showed a preferential limbic-related expression pattern for these transcripts. The ERalpha mRNA dominates in the amygdala and hypothalamus, suggesting estrogen modulation of autonomic and neuroendocrine as well as emotional functions. In contrast, the hippocampal formation, entorhinal cortex, and thalamus appear to be ERbeta-dominant areas, suggesting a role for ERbeta in cognition, non-emotional memory, and motor functions. The role of estradiol can also be examined in regard to its relationship to other neurotransmitter systems known to be linked to specific psychiatric disorders. Estradiol has been shown to regulate the serotonin (5-HT) system, which has been strongly implicated in affective disorders. We have studied a genetic animal model of depression, and found altered 5-HT receptor mRNA levels in discrete brain regions; many of the abnormalities are reversed by estradiol treatment, especially for the 5-HT(2A) receptor subtype. The norepinephrine (NE) system is, similar to serotonin, a target for antidepressant drugs, and projects to mesocorticolimbic structures implicated in mood disorders. We have recently observed that NE neurons in the human locus coeruleus (LC) express moderate levels of both ER transcripts. The possibility of estrogen's regulating LC function has been documented in animal studies. Results from our preliminary experiments have revealed that the ERbeta mRNA is decreased in persons committing suicide, a cause of death that is highly linked to affective disorder. Follow-up studies are currently under way with a much larger population to validate these results. Overall, the discrete anatomical organization of the ER mRNAs in the human brain provide evidence as to the specific neuronal populations in which the actions of ERs could modulate mood and thus underlie the neuropathology of psychiatric disorders such as depression.

Opioid receptors are critical for heroin dependence, and A118G SNP of the opioid receptor gene (OPRM1) has been linked with heroin abuse. In our population of European Caucasians (n ‫؍‬ 118), Ϸ90% of 118G allelic carriers were heroin users. Postmortem brain analyses showed the OPRM1 genotype associated with transcription, translation, and processing of the human striatal opioid neuropeptide system. Whereas down-regulation of preproenkephalin and preprodynorphin genes was evident in all heroin users, the effects were exaggerated in 118G subjects and were most prominent for preproenkephalin in the nucleus accumbens shell. Reduced opioid neuropeptide transcription was accompanied by increased dynorphin and enkephalin peptide concentrations exclusively in 118G heroin subjects, suggesting that the peptide processing is associated with the OPRM1 genotype. Abnormal gene expression related to peptide convertase and ubiquitin͞proteosome regulation was also evident in heroin users. Taken together, alterations in opioid neuropeptide systems might underlie enhanced opiate abuse vulnerability apparent in 118G individuals.drug abuse ͉ dynorphin ͉ enkephalin ͉ mRNA

Plasma tau and NF-L concentrations are strongly increased in CJD and show similar diagnostic performance to the corresponding CSF measure. Molecular subtypes of sporadic CJD show different levels of plasma tau. Although not disease-specific, these findings support the use of plasma tau and NF-L as tools to identify, or to rule out, neurodegeneration.

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Background Opiate abuse and overdose reached epidemic levels in the USA. However, despite significant advances in animal and in vitro models, little knowledge has been directly accrued regarding the neurobiology of the opiate-addicted human brain. Methods We used post-mortem human brain specimens from a homogeneous European Caucasian population of heroin users for transcriptional and epigenetic profiling as well as direct assessment of chromatin accessibility in the striatum, a brain region central to reward and emotion. A rat heroin self-administration model was used to obtain translational molecular and behavioral insights. Results Our transcriptome approach revealed marked impairments related to glutamatergic neurotransmission and chromatin remodeling in the human striatum. A series of biochemical experiments tracked the specific location of the epigenetic disturbances to hyperacetylation of lysine 27 (H3K27ac) of histone H3, showing dynamic correlations with heroin use history and acute opiate toxicology. Targeted investigation of GRIA1, a glutamatergic gene implicated in drug-seeking behavior, verified the increased enrichment of H3K27ac at discrete loci, accompanied by enhanced chromatin accessibility at hyperacetylated regions in the gene body. Analogous epigenetic impairments were detected in the striatum of heroin self-administering rats. Using this translational model, we showed that bromodomain inhibitor JQ1, which blocks the functional read-out of acetylated lysines, reduced heroin self-administration and cue-induced drug-seeking behavior. Conclusions Overall, our data suggest that heroin-related histone H3 hyperacetylation contributes to glutamatergic transcriptional changes that underlie addiction behavior and identify JQ1 as a promising candidate for targeted clinical interventions in heroin use disorder.