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Cell type-specific effects of adenosine on cortical neurons.

van Aerde KI, Qi G, Feldmeyer D - Cereb. Cortex (2013)

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.

View Article: PubMed Central - PubMed

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.

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Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. (A) Morphological reconstruction of the soma and dendrites from pyramidal neurons in layers 2 and 5 of the somatosensory cortex. Inset at left bottom shows an example staining with layer borders indicated as dotted lines. (B) Left, average response of the RMP of excitatory neurons in layers 2 and 5 during bath application of 100 μM adenosine (start at arrow). Right, average adenosine-induced hyperpolarization of layer 2 pyramidal neurons (n = 5) and layer 5 pyramidal neurons (n = 15). (C) Example trace of the RMP during application of 100 μM adenosine, followed by coapplication of 5 μM A1R antagonist CPT. Right, average responses during control (con) and 100 μM adenosine (ado) conditions, and during coapplication of 1–5 μM CPT (n = 5). (D) Adenosine-induced hyperpolarization of the RMP for layer 5 pyramidal neuron subtypes (slender tufted, n = 6; broad tufted, n = 3; untufted, n = 6). Sublaminar location of neurons is indicated for layer 5A (upward triangles) or 5B (downward filled triangles). *P < 0.05, **P < 0.01.
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BHT274F7: Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. (A) Morphological reconstruction of the soma and dendrites from pyramidal neurons in layers 2 and 5 of the somatosensory cortex. Inset at left bottom shows an example staining with layer borders indicated as dotted lines. (B) Left, average response of the RMP of excitatory neurons in layers 2 and 5 during bath application of 100 μM adenosine (start at arrow). Right, average adenosine-induced hyperpolarization of layer 2 pyramidal neurons (n = 5) and layer 5 pyramidal neurons (n = 15). (C) Example trace of the RMP during application of 100 μM adenosine, followed by coapplication of 5 μM A1R antagonist CPT. Right, average responses during control (con) and 100 μM adenosine (ado) conditions, and during coapplication of 1–5 μM CPT (n = 5). (D) Adenosine-induced hyperpolarization of the RMP for layer 5 pyramidal neuron subtypes (slender tufted, n = 6; broad tufted, n = 3; untufted, n = 6). Sublaminar location of neurons is indicated for layer 5A (upward triangles) or 5B (downward filled triangles). *P < 0.05, **P < 0.01.

Mentions: The definition of cortical layers in the medial prefrontal cortex (mPFC) is described in great detail in our accompanying study (Van Aerde and Feldmeyer 2013). In short, layer borders were drawn under low-magnification conditions using maximal contrast. The embedding of slices in Eukitt (see above) prevented fading of cytoarchitectural features and improved the contrast between layers considerably (Marx et al. 2012). Layer borders were defined based on cytoarchitectural features of which cell density and cell soma size were most important in agreement with earlier studies of the prefrontal cortex (Van Eden and Uylings 1985; Gabbott et al. 1997, 2005). In the somatosensory cortex, granular layer 4 can be seen as a darker band with barrel-like structures. Layer 2/3 is situated supragranular, and layer 5 is situated subgranular. Sublamina 5A and 5B can be easily distinguished in fixed slices: Sublamina 5A is bordered between the darker layers 4 and 5B (see inset in Fig. 7A).


Cell type-specific effects of adenosine on cortical neurons.

van Aerde KI, Qi G, Feldmeyer D - Cereb. Cortex (2013)

Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. (A) Morphological reconstruction of the soma and dendrites from pyramidal neurons in layers 2 and 5 of the somatosensory cortex. Inset at left bottom shows an example staining with layer borders indicated as dotted lines. (B) Left, average response of the RMP of excitatory neurons in layers 2 and 5 during bath application of 100 μM adenosine (start at arrow). Right, average adenosine-induced hyperpolarization of layer 2 pyramidal neurons (n = 5) and layer 5 pyramidal neurons (n = 15). (C) Example trace of the RMP during application of 100 μM adenosine, followed by coapplication of 5 μM A1R antagonist CPT. Right, average responses during control (con) and 100 μM adenosine (ado) conditions, and during coapplication of 1–5 μM CPT (n = 5). (D) Adenosine-induced hyperpolarization of the RMP for layer 5 pyramidal neuron subtypes (slender tufted, n = 6; broad tufted, n = 3; untufted, n = 6). Sublaminar location of neurons is indicated for layer 5A (upward triangles) or 5B (downward filled triangles). *P < 0.05, **P < 0.01.
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BHT274F7: Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. Heterogeneity of adenosine sensitivity is also apparent in rat somatosensory cortex. (A) Morphological reconstruction of the soma and dendrites from pyramidal neurons in layers 2 and 5 of the somatosensory cortex. Inset at left bottom shows an example staining with layer borders indicated as dotted lines. (B) Left, average response of the RMP of excitatory neurons in layers 2 and 5 during bath application of 100 μM adenosine (start at arrow). Right, average adenosine-induced hyperpolarization of layer 2 pyramidal neurons (n = 5) and layer 5 pyramidal neurons (n = 15). (C) Example trace of the RMP during application of 100 μM adenosine, followed by coapplication of 5 μM A1R antagonist CPT. Right, average responses during control (con) and 100 μM adenosine (ado) conditions, and during coapplication of 1–5 μM CPT (n = 5). (D) Adenosine-induced hyperpolarization of the RMP for layer 5 pyramidal neuron subtypes (slender tufted, n = 6; broad tufted, n = 3; untufted, n = 6). Sublaminar location of neurons is indicated for layer 5A (upward triangles) or 5B (downward filled triangles). *P < 0.05, **P < 0.01.
Mentions: The definition of cortical layers in the medial prefrontal cortex (mPFC) is described in great detail in our accompanying study (Van Aerde and Feldmeyer 2013). In short, layer borders were drawn under low-magnification conditions using maximal contrast. The embedding of slices in Eukitt (see above) prevented fading of cytoarchitectural features and improved the contrast between layers considerably (Marx et al. 2012). Layer borders were defined based on cytoarchitectural features of which cell density and cell soma size were most important in agreement with earlier studies of the prefrontal cortex (Van Eden and Uylings 1985; Gabbott et al. 1997, 2005). In the somatosensory cortex, granular layer 4 can be seen as a darker band with barrel-like structures. Layer 2/3 is situated supragranular, and layer 5 is situated subgranular. Sublamina 5A and 5B can be easily distinguished in fixed slices: Sublamina 5A is bordered between the darker layers 4 and 5B (see inset in Fig. 7A).

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.

View Article: PubMed Central - PubMed

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