Fig. 4: Ovoid neurons have heightened excitability, consistent with specialized morphology.
From: Atypical hippocampal excitatory neurons express and govern object memory
A Left: Ovoid cell morphology from ex vivo whole-cell recording. Inset provides expanded cell body. B As in (A), but for pyramidal cells. Inset shows bursting. C Input resistances for ovoid neurons, regular spiking pyramidal neurons, and burst spiking pyramidal neurons (n = 75 ovoid cells, n = 24 regular spiking pyramidal cells, n = 28 burst spiking pyramidal cells, n = total 67 animals; ovoid vs. regular spiking pyramidal p = 6.1e-8, ovoid vs. burst spiking pyramidal p = 6.1e-8, regular spiking pyramidal vs. burst spiking pyramidal p = 5.9e-3, Kruskal-Wallis test on averaged data from individual animals). Data points are averages from individual animals and data are presented as mean values ± SEM. D As in (C), but for rheobase of cells (ovoid vs. pyramidal regular spiking p = 1.9e-6, ovoid vs. burst spiking pyramidal p = 3.9e-5, regular spiking pyramidal vs. burst spiking pyramidal p = 1.4e-1, Kruskal-Wallis test). E Input-output curves for ovoid and pyramidal neurons, with regular spiking and bursting neurons pooled for pyramidal neurons (n = 71 ovoid, n = 70 pyramidal cells, n = 67 animals; 0pA p = 1, 20pA p = 2.4e-2, 40pA p = 2.7e-7, 60pA p = 9.7e-10, 80pA p = 1.0e-9, 100pA p = 1.1e-10 on averaged data from individual animals, two-sided Mann-Whitney U test). Data are presented as mean values ± SEM. F Left: Reconstructed morphology of an ovoid neuron used for simulation. Right: action potential firing for ovoid neuron following current injection. Scale bars: 20 mV and 250 ms. G As in (F), but for a pyramidal neuron, with radial oblique dendrites colored in violet. Overlaid traces depict simulations with radial obliques (“normal morphology”) and without radial obliques (“obliqueless”). H Input resistances for modeled ovoid neurons (n = 9), pyramidal neurons with radial obliques (“normal morphology”, n = 10), and pyramidal neurons without radial oblique dendrites (“obliqueless”, n = 10). Data points are individual modeled neurons and data are presented as mean values ± SEM.
