Dendritic morphology and inhibitory regulation distinguish dentate semilunar granule cells from granule cells through distinct stages of postnatal development

Gupta, Akshay; Proddutur, Archana; Chang, Yun‐Juan; Raturi, Vidhatri; Guevarra, Jenieve; Shah, Yash; Elgammal, Fatima S.; Santhakumar, Vijayalakshmi

doi:10.1007/s00429-020-02162-y

Cited by 14 publications

(47 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Morphometric parameters from putative GCs (Clusters #1 and #2) were pooled together and compared with Cluster #3 (putative SGCs) for further analysis. Similar to findings in rats (Gupta et al ., 2020), GCs and SGCs differed in dendritic angle, number of primary dendrites, soma aspect ratio and dendritic complexity (Fig. 1, Table S3,4).…”

Section: Resultssupporting

confidence: 91%

“…Unsupervised clustering of morphometric data obtained from reconstruction of neurons in which dendritic arbors were fully recovered was used to verify whether the somato-dendritic parameters distinguishing GCs from SGCs in mice are similar to those characterized in rats (Gupta et al ., 2020; Williams et al ., 2007). Projection neurons were identified based on the presence of spiny dendrites in the molecular layer and axons with mossy fiber boutons entering the hilus and targeting CA3 (Gupta et al ., 2020). Morphometric parameters of the cells reconstructed in 3D were obtained using automated algorithms in Neurolucida Explorer (Tables S1-2, adapted from Gupta et al ., 2020).…”

Section: Resultsmentioning

confidence: 99%

“…Projection neurons were identified based on the presence of spiny dendrites in the molecular layer and axons with mossy fiber boutons entering the hilus and targeting CA3 (Gupta et al ., 2020). Morphometric parameters of the cells reconstructed in 3D were obtained using automated algorithms in Neurolucida Explorer (Tables S1-2, adapted from Gupta et al ., 2020). Principal Component Analysis (PCA) of 42 morphometric parameters from 17 cells revealed that the first two principal components (PCs) explained more than 50% of the total variance in the data, while the first seven components explained 90% of the variance (Fig S2A).…”

Section: Resultsmentioning

confidence: 99%

“…Although dentate GCs have, for long, been considered a structurally and functionally uniform class of projection neurons, detailed morphometric and physiological analysis in rats have revealed a sparse, structurally distinct population of projection neurons described as semilunar granule cells (SGCs) by Ramón y Cajal (1995) (Gupta et al, 2012; Gupta et al, 2020; Save et al, 2018; Williams et al, 2007). Functionally, SGCs have sustained firing in response to afferent stimulation, which distinguish them from GCs (Larimer and Strowbridge, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…Of particular relevance to dentate inhibitory regulation, whether SGCs receive similar early (feedforward or disynaptic feedback) as well as sustained polysynaptic feedback inhibition as GCs or may escape this inhibitory gate is currently unknown. Studies in adolescent rats show that SGCs have higher tonic GABA currents and receive more frequent synaptic inhibitory inputs than GCs (Gupta et al ., 2012; Gupta et al ., 2020). Uniquely, SGCs show reduction in both tonic GABA currents and frequency of synaptic inhibitory inputs after brain injury rather than the increase observed in GCs (Gupta et al ., 2012).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Differential Activity-Dependent Increase in Synaptic Inhibition and Parvalbumin Interneuron Recruitment in Dentate Granule Cells and Semilunar Granule Cells

Afrasiabi

Gupta

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Strong inhibitory synaptic gating of dentate gyrus granule cells (GCs), attributed largely to fast-spiking parvalbumin interneurons (PV-INs), is essential to maintain sparse network activity needed for dentate dependent behaviors. However, the contribution of PV-INs to basal and input driven sustained synaptic inhibition in GCs and semilunar granule cells (SGCs), a sparse morphologically distinct dentate projection neuron subtype are currently unknown. We find that although basal inhibitory postsynaptic currents (IPSCs) are more frequent in SGCs and optical activation of PV-INs elicited IPSCs in both GCs and SGCs, optical suppression of PV-INs failed to reduce IPSC frequency in either cell type. Amplitude and kinetics of IPSCs evoked by perforant path activation were not different between GCs and SGCs. However, the robust increase in sustained polysynaptic IPSCs elicited by paired afferent stimulation was lower in SGCs than in simultaneously recorded GCs. Optical suppression of PV-IN selectively reduced sustained IPSCs in SGCs but not in GCs. These results demonstrate that PV-INs, while contributing minimally to basal synaptic inhibition in both GCs and SGCs in slices, mediate sustained feedback inhibition selectively in SGCs. The temporally selective blunting of activity-driven sustained inhibitory gating of SGCs could support their preferential and persistent recruitment during behavioral tasks.

show abstract

Section: Resultssupporting

confidence: 91%