Neuroscience
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Auditory verbal hallucinations (AVHs) frequently occur across multiple psychiatric diseases especially in schizophrenia (SCZ) patients. Functional imaging studies have revealed the hyperactivity of the auditory cortex and disrupted auditory-verbal network activity underlying AVH etiology. This review will firstly summarize major findings from both human AVH patients and animal models, with focuses on the auditory cortex and associated cortical/sub-cortical areas. ⋯ However, we can still extract useful information from animal SCZ models based on the disruption of auditory pathway during AVH episodes. Therefore, we will further interpolate the synaptic structures and molecular targets, whose dysregulation in SCZ models may be highly related with AVH episodes. As the last part, implications for future development of treatment strategies will be discussed.
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Prescription opioid abuse is a serious public health issue. Recently, we showed that female and male Sprague-Dawley rats acquire conditioned place preference (CPP) to the mu opioid receptor agonist oxycodone. Anatomical analysis of the hippocampus from these rats unveiled sex differences in the opioid system in a way that would support excitation and opiate associative learning processes especially in females. ⋯ Oxycodone CPP females have: a) increases in ARC (activity regulated cytoskeletal-associated protein)-immunoreactivity (ir) in CA3 pyramidal cells; b) decreases in Npy (neuropeptide Y) gene expression in the medial hippocampus but higher numbers of NPY-containing hilar interneurons compared to males; c) increases in Crhr2 (corticotropin releasing factor receptor 2) expression in CA2/3; d) increases in Akt1 (AKT serine/threonine kinase 1) expression in medial hippocampus; and e) decreases in phosphorylated MAPK (mitogen activated protein kinase)-ir in CA1 and dentate gyrus. Oxycodone CPP males have: a) increases in Bdnf (brain derived-neurotrophic factor) expression, which is known to be produced in granule cells, relative to females; b) elevated Mapk1 expression and pMAPK-ir in the dentate hilus which harbors newly generated granule cells; and c) increases in CRHR1-ir in CA3 pyramidal cell soma. These sex-specific changes in plasticity, stress and kinase markers in hippocampal circuitry parallel previously observed sex differences in the opioid system after oxycodone CPP.
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Previous studies have found that native Chinese speakers recruit the bilateral fusiform gyrus to read English words, in the same manner as they read Chinese words (i.e., the assimilation process). In this study, we quantified the neural pattern similarity between native (L1) and second languages (L2) by using representational similarity analysis (RSA), and examined the modulatory effects of L2 proficiency on cross-language neural pattern similarity (PS) in the bilateral fusiform cortex. Results showed that, for Chinese-English bilinguals, higher reading proficiency in L2 was associated with greater cross-language PS in the left fusiform gyrus, but with lower PS in the right fusiform gyrus. These results suggest that, as L2 proficiency increases, the assimilation process is enhanced in the region for word reading (left fusiform gyrus), but reduced in the region for nonlinguistic processing (right fusiform gyrus).
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Memories are acquired and stored in two forms, short-term memory (STM) and long-term memory (LTM). For the consolidation of LTM, de novo protein synthesis is required, which are also known as plasticity related proteins. Long-term potentiation is a form of synaptic plasticity and it is considered as a cellular model of learning and memory. ⋯ Despite being studied for LTM formation for many years, no studies so far have investigated the role of PKM-ζ in Behavioral tagging model. Hence, by using these two different memories based tasks (i.e., Inhibitory avoidance and Novel object recognition tasks), we observed how PKM-ζ activated by exposing a novel arena after a weak training and led to the consolidation of memory. These findings thus show how the process of behavioral tagging activates Long-term potentiation -specific PKM-ζ for the formation of LTM.
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Medullary dorsal horn (MDH), the homolog of spinal dorsal horn, plays essential roles in processing of nociceptive signals from orofacial region toward higher centers, such as the ventral posteromedial thalamic nucleus (VPM) and parafascicular thalamic nucleus (Pf), which belong to the sensory-discriminative and affective aspects of pain transmission systems at the thalamic level, respectively. In the present study, in order to provide morphological evidence for whether neurons in the MDH send collateral projections to the VPM and Pf, a retrograde double tracing method combined with immunofluorescence staining for substance P (SP), SP receptor (SPR) and Fos protein was used. Fluoro-gold (FG) was injected into the VPM and the tetramethylrhodamine-dextran (TMR) was injected into the Pf. ⋯ It was also found that some of the FG/TMR double-labeled neurons within lamina I expressed SPR and were in close contact with SP-immunoreactive (SP-ir) terminals. After formalin injection into the orofacial region, 41.4% and 34.3% of the FG/TMR double-labeled neurons expressed Fos protein in laminae I and III, respectively. The present results provided morphological evidence for that some SPR-expressing neurons within the MDH send collateral projections to both VPM and Pf and might be involved in sensory-discriminative and affective aspects of acute orofacial nociceptive information transmission.