GABAergic Precursor Transplantation into the Prefrontal Cortex Prevents Phencyclidine-Induced Cognitive Deficits
ABSTRACT Phencyclidine (PCP) is a noncompetitive NMDA receptor antagonist, and it induces schizophreniform cognitive deficits in healthy humans and similar cognitive deficits in rodents. Although the PCP-induced cognitive deficits appear to be accompanied and possibly caused by dysfunction of GABAergic inhibitory interneurons in the prefrontal cortex (PFC), the potential benefit(s) of GABAergic interneuron manipulations on PCP-induced cognitive deficits remains unexplored. In this study we show that when embryonic medial ganglionic eminence (MGE) cells, many of which differentiate into cortical GABAergic interneurons in situ, were grafted into the medial PFC (mPFC) of neonatal mice, they differentiated into a specific class of GABAergic interneurons and became functionally integrated into the host neuronal circuitry in adults. Prior MGE cell transplantation into the mPFC significantly prevented the induction of cognitive and sensory-motor gating deficits by PCP. The preventive effects were not reproduced by either transplantation of cortical projection neuron precursors into the mPFC or transplantation of MGE cells into the occipital cortex. The preventive effects of MGE cell transplantation into the mPFC were accompanied by activation of callosal projection neurons in the mPFC. These findings suggest that increasing GABAergic interneuron precursors in the PFC may contribute to the development of a cell-based approach as a novel means of modulating the PFC neuronal circuitry and preventing schizophreniform cognitive deficits.
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- "DOI:10.1523/JNEUROSCI.0693-14.2014 Copyright © 2014 the authors 0270-6474/14/349506-10$15.00/0 Southwell et al., 2010; Alvarez Dolado and Broccoli, 2011; Tanaka et al., 2011; Bráz et al., 2012 "
ABSTRACT: GABAergic inhibition has been shown to play an important role in the opening of critical periods of brain plasticity. We recently have shown that transplantation of GABAergic precursors from the embryonic medial ganglionic eminence (MGE), the source of neocortical parvalbumin- (PV(+)) and somatostatin-expressing (SST(+)) interneurons, can induce a new period of ocular dominance plasticity (ODP) after the endogenous period has closed. Among the diverse subtypes of GABAergic interneurons PV(+) cells have been thought to play the crucial role in ODP. Here we have used MGE transplantation carrying a conditional allele of diphtheria toxin alpha subunit and cell-specific expression of Cre recombinase to deplete PV(+) or SST(+) interneurons selectively and to investigate the contributions of each of these types of interneurons to ODP. As expected, robust plasticity was observed in transplants containing PV(+) cells but in which the majority of SST(+) interneurons were depleted. Surprisingly, transplants in which the majority of PV(+) cells were depleted induced plasticity as effectively as those containing PV(+) cells. In contrast, depleting both cell types blocked induction of plasticity. These findings reveal that PV(+) cells do not play an exclusive role in ODP; SST(+) interneurons also can drive cortical plasticity and contribute to the reshaping of neural networks. The ability of both PV(+) and SST(+) interneurons to induce de novo cortical plasticity could help develop new therapeutic approaches for brain repair.Proceedings of the National Academy of Sciences 12/2014; 111(51). DOI:10.1073/pnas.1421844112 · 9.81 Impact Factor
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ABSTRACT: Schizophrenia is a severe and common psychiatric disease with a lifetime prevalence of 0.5% to 1% globally. Because of limitations of the experimental approach in humans, valid animal models are essential in the effort to identify novel therapeutics for schizophrenia. In most animal models of schizophrenia, second generation antipsychotic drugs are reported to be effective in ameliorating behavioral abnormalities, while clinical evidence indicates that some of the patients are resistant to the antipsychotic drug therapy. Accordingly, animal models of antipsychotic drug-resistant schizophrenia are needed for screening of novel agents that may be more effective than the existing antipsychotic drugs. Furthermore, utilization of appropriate behavioral tasks with reference to human testing is essential to facilitate the development of novel pharmacotherapeutic approaches for the treatment in schizophrenia. Experimental data suggest that there are different types of potential candidate molecules as novel antipsychotic drugs with some therapeutic effects on negative symptoms and cognitive deficits in schizophrenia. It is proposed that to develop novel antipsychotic drugs the efficacy of potential candidate molecules should be evaluated using animal models for treatment-resistant schizophrenia with appropriate behavioral tasks in reference to human testing.Neurobiology of Disease 11/2012; DOI:10.1016/j.nbd.2012.10.025 · 5.20 Impact Factor
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ABSTRACT: GABAergic interneurons of the cerebral cortex (cINs) play crucial roles in many aspects of cortical function. The diverse types of cINs are classified into subgroups according to their morphology, intrinsic physiology, neurochemical markers and synaptic targeting. Recent advances in mouse genetics, imaging and electrophysiology techniques have greatly advanced our efforts to understand the role of normal cIN function and its dysfunction in neuropsychiatric disorders. In schizophrenia (SCZ), a wealth of data suggests that cIN function is perturbed, and that interneuron dysfunction may underlie key symptoms of the disease. In this review, we discuss the link between cINs and SCZ, focusing on the evidence for GABAergic signaling deficits from both SCZ patients and mouse models.Neurobiology of Disease 11/2012; 53. DOI:10.1016/j.nbd.2012.11.013 · 5.20 Impact Factor