Generation Of GABAergic Neurons Research Articles

Directing Astroglia from the Cerebral Cortex into Subtype Specific Functional Neurons

Author SummaryThe brain consists of two major cell types: neurons, which transmit information, and glial cells, which support and protect neurons. Interestingly, evidence suggests that some glial cells, including astroglia, can be directly converted into neurons by specific proteins, a transformation that may aid in the functional repair of damaged brain tissue. However, in order for the repaired brain areas to function properly, it is important that astroglia be directed into appropriate neuronal subclasses. In this study, we show that non-neurogenic astroglia from the cerebral cortex can be reprogrammed in vitro using just a single transcription factor to yield fully functional excitatory or inhibitory neurons. We achieved this result through forced expression of the same transcription factors that instruct the genesis of these distinct neuronal subtypes during embryonic forebrain development. Moreover we demonstrate that reactive astroglia isolated from the adult cortex after local injury can be reprogrammed into synapse-forming excitatory or inhibitory neurons following a similar strategy. Our findings provide evidence that endogenous glial cells may prove a promising strategy for replacing neurons that have degenerated due to trauma or disease.

Generation of gabaergic neurons from mouse embryonic stem cells by combination of high‐retinoid acid and extracellular matrix

Generation of gabaergic neurons from mouse embryonic stem cells by combination of high‐retinoid acid and extracellular matrix

Earliest spontaneous activity differentially regulates neocortical GABAergic interneuron subpopulations

Although less than one quarter of all neurons in the cerebral cortex are GABAergic, these neurons are morphologically diverse and their physiological complexity decisively moulds the network physiology. An important question is how different subpopulations of GABAergic neurons are regulated numerically during development. In rat neocortical cultures, neuronal precursors continue to divide, generating both GABAergic and non-GABAergic neurons. In vitro generated GABAergic neurons form a population of uniquely small, mostly fusiform neurons that differ in size and morphology from older, in situ generated, large stellate GABAergic neurons. In a large series of experiments we investigated the impact of neuronal activity on the development of these two subpopulations of GABA interneurons present in cortical networks during the first 2 weeks in vitro. Here we show that a moderate increase in the generation of GABAergic neurons was achieved by blocking activity with tetrodotoxin, indicating that intrinsic spontaneous activity inhibits GABAergic neurogenesis in culture. Antagonists to ionotropic glutamate receptor and/or GABA(A) receptor did not significantly alter GABAergic generation but agonists to these receptors showed a time-sensitive regulation of the size of small and large GABAergic neuronal subpopulations. Further, our results indicate that alterations of cell generation by activity manipulations might be overwritten by later activity effects on the survival of GABAergic cell populations.