Cell type-specific effects of adenosine on cortical neurons.
Bottom Line: Although the effect of adenosine on subcortical areas has been previously described, the effects on cortical neurons have not been addressed systematically to date.We found that adenosine, via the A1 receptor, exerts differential effects depending on neuronal cell type and laminar location.These studies of the action of adenosine at the postsynaptic level may contribute to the understanding of the changes in cortical circuit functioning that take place between sleep and awakening.
Affiliation: Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Current address: Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Science, 1105 BA Amsterdam, The Netherlands.Show MeSH
Mentions: L5 pyramidal neurons of the prefrontal cortex can be categorized according to their electrophysiological and morphological properties (Yang et al. 1996; Degenetais et al. 2002; Wang et al. 2006; Chang and Luebke 2007). In addition, retrograde labeling studies show that specific electrophysiological cell types have distinct projection areas: RS neurons mainly project onto the thalamus and pontine nuclei in the brainstem, whereas neurons with adapting spike trains preferentially innervate the ipsi- and contralateral striatum or contralateral cortex (Dembrow et al. 2010; Gee et al. 2012). We have classified layer 5 pyramidal neurons into 4 groups: (1) Broad tufted RS neurons that show little adaptation, with the exception of the first ISI, a high threshold for firing, low-input resistance, and a short time constant; (2) slender tufted adapting neurons that show more adaptation have a low threshold for firing, high input resistance, and a long time constant (“adapting high-resistance neurons,” Ad-HR), (3) slender tufted adapting neurons with intermediate values for input resistance, rheobase, and time constant (“adapting low-resistance neurons,” Ad-LR), and finally, (4) pyramidal neurons that are characterized by a very wide field span of the basal dendrites (“wide” neurons). Note, however, that this last subtype is rare (∼6% of L5 neurons; Fig. 4A; Van Aerde and Feldmeyer 2013).Figure 4.
Affiliation: Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Current address: Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Science, 1105 BA Amsterdam, The Netherlands.