Layer V Neocortical Pyramidal Neuron
Layer V pyramidal cell from cat association cortex. This cell was stained with neurobiotin and reconstructed using a X100 objective (Neurolucida). The physiology, morphology and modeling of that cell are described in: Rudolph M, Pelletier J-G, Paré D and Destexhe A. (2005) Characterization of synaptic conductances and integrative properties during electrically-induced EEG-activated states in neocortical neurons in vivo. Journal of Neurophysiology 94: 2805-2821.
This cell has 4 primary dendritic branches with a total area of 22481 square-microns. The staining was not very sharp, so the reconstruction may have missed parts of the distal dendrites. The geometry was corrected for tissue shrinkage. Some spines were visible in the optical microscope (X100).
Layer V Neocortical Pyramidal Neuron
Layer V pyramidal cell from cat somatosensory cortex. This cell was stained with neurobiotin and reconstructed using a X100 objective. The physiology, morphology and modeling of that cell are described in: Contreras D, Destexhe A and Steriade M (1997) Intracellular and computational characterization of the intracortical inhibitory control of synchronized thalamic inputs in vivo. Journal of Neurophysiology 78: 335-350.
This cell has 9 primary dendritic branches with a total dendritic length of 22173 microns and an area of 91620 square-microns. The staining was very sharp and the reconstruction could be made accurately for all dendrites. The total membrane area of this cell is exceptionally large. With a density of 0.6 spines per square micron (Larkman AU, J. Comp. Neurol. 306: 332-343, 1991), this cells probably receives about 50,000 spines. Spines were indeed visible in the optical microscope (X100).
Layer VI Neocortical Pyramidal Neuron
Layer VI pyramidal cell from cat somatosensory cortex. This cell was stained with neurobiotin and reconstructed using a X100 objective. The physiology of that cell and the modeling are described in: Contreras D, Destexhe A and Steriade M (1997) Intracellular and computational characterization of the intracortical inhibitory control of synchronized thalamic inputs in vivo. Journal of Neurophysiology 78: 335-350.
This cell has 5 primary dendritic branches with a total dendritic length of 7576 microns and an area of 31225 square-microns. The cell was very sharply stained and the reconstruction could be done accurately. The fact that the apical trunk does not arborize in superficial layers did not appear to be a consequence of the staining or reconstruction procedure. Spines were visible in the optical microscope (X100).
Thalamic Relay Neuron
Thalamocortical relay neuron from rat ventrobasal nucleus. This cell was stained with biocytin. The neuron is described in: Huguenard JR and Prince DA (1992) A novel T-type current underlies prolonged calcium-dependent burst firing in GABAergic neurons of rat thalamic reticular nucleus. Journal of Neuroscience 12: 3804-3817. The morphology, passive cable properties and modeling of this neuron are described in: Destexhe A, Neubig M, Ulrich D and Huguenard JR (1998) Dendritic low-threshold calcium currents in thalamic relay cells. Journal of Neuroscience 18: 3574-3588.
This cell has 11 primary dendrites, having a total length of 7095 microns; the total membrane area is 23980.5 square-microns, including 2625 square-microns for the soma which is about 20-25 micron diameter. The tracing of the diameters of some distal dendrites could not be performed precisely due to biocytin artifacts although lengths and branching patterns were accurately reconstructed. In those cases, the diameters were artificially rescaled such as to match the diameter profile of dendritic segments that could be reconstructed accurately. The dendritic arborizations tend to be organized in a bush-like structure, similar to previous morphological observations (Jones EG, The Thalamus, Plenum Press, New York, 1985).
Thalamic Reticular Neuron
Thalamic reticular cell, from the reticular sector of rat ventrobasal nucleus. This cell was stained with biocytin. The neuron is described in: J.R. Huguenard & D.A. Prince, A novel T-type current underlies prolonged calcium-dependent burst firing in GABAergic neurons of rat thalamic reticular nucleus. (1992) J. Neurosci. 12: 3804-3817. The morphology, passive cable properties and modeling of this neuron are described in: Destexhe A, Contreras D, Steriade M, Sejnowski TJ and Huguenard JR (1996) In vivo, in vitro and computational analysis of dendritic calcium currents in thalamic reticular neurons. Journal of Neuroscience 16: 169-185.
This cell has 4 primary dendrites, having a total length of 3785 microns; the total membrane area is 15,115 square-microns, including 1760 square-microns for the soma which has a diameter of about 20-25 microns. The dendritic arborizations tends to spread in planes parallel to the long axis of the thalamic reticular nucleus, as described previously (Ramon y Cajal S, Histologie du Système Nerveux de l'Homme et des Vertébrés, Maloine, Paris, 1909). The staining was very sharp and the reconstruction could be made accurately (X100 objective) for the entire dendritic tree. No spines were visible in the optical microscope.