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. Author manuscript; available in PMC: 2014 Jun 19.
Published in final edited form as: Neuron. 2013 Jun 19;78(6):10.1016/j.neuron.2013.04.025. doi: 10.1016/j.neuron.2013.04.025

Figure 6. Neurosecretory-Presympathetic Crosstalk Unveiled during Dual-Patch Recordings from EGFP-VP and PVN-RVLM Neurons.

Figure 6

(A) Sample pair of intracellularly labeled (Alexa 633; blue, arrows) PVN neurons during simultaneous dual-patch recordings. The identity of the patched neurons as EGFP-VP (cyan, single arrow) and retrogradely labeled PVN-RVLM (purple, double arrow) is shown in (A2).

(B) Electrically evoked bursting activity in the EGFP-VP neuron resulted in a delayed membrane depolarization and increased firing discharge in the neighboring PVN-RVLM neuron. Note the pronounced AHP following action potential firing in the EGFP-VP neuron (filled arrowhead). (B2) Another sample of paired recordings showing a similar response. Note, however, the lack of AHP in the EGFP-VP neuron (empty arrowhead) and the shorter latency of the evoked PVN-RVLM response.

(C) Sample of a paired recording in which the EGFP-VP neuron was dialyzed with BAPTA. Note the lack of response in the PVN-RVLM neuron.

(D) Sample of a paired recording in the presence of L-AAA (250 μM, 30 min), showing an increase in PVN-RVLM firing activity following stimulation of the EGFP-VP neuron. Note the presence of a DAP in the EGFP-VP neuron (double filled arrowheads) and the brief latency for the evoked PVN-RVLM response.

(E) Comparison of the mean interneuronal-coupling latency in EGFP-VP neurons displaying or not an AHP following the evoked burst of action potentials (n = 10 and 8, respectively).

(F) Summary data of mean changes in PVN-RVLM membrane potential (left) and firing activity (right) following direct stimulation of EGFP-VP neurons in control ACSF (n = 13), V1a antagonist (n = 7), intracellular BAPTA in the stimulated EGFP-VP neuron (n = 5), and in the presence of L-AAA (n = 5).

(G) Another representative example of dual-patched and intracellularly labeled EGFP and PVN-RVLM neurons. (G1) Single focal plane of a confocal image showing EGFP-VP (green) and PVN-RVLM (red) neurons. The recorded PVN-RVLM neuron was intracellularly filled with Alexa 633 (arrow; colocalization is indicated in purple), and the recorded EGFP-VP neuron was intracellularly filled with Alexa Fluor 555 (arrowhead; colocalization is indicated in yellow). (G2) is the same image as in (A1), but a confocal stack of ten images is shown to better depict the dendritic processes of the recorded neurons. The blue color has been transformed to white for better clarity. Asterisk points to a dendritic end of the EGFP-VP (Alexa Fluor 555; filled) neuron. In (G3), the squared area in (G2) is shown at a magnified scale.

Error bars represent SEM. **p < 0.001 versus AHP; +p < 0.05 and #p < 0.01 versus V1a antagonist and BAPTA, respectively. Scale bars represent 25 μm in (A1), 20 μm in (G1) and (G2), and 10 μm in (G3). Action potentials were cropped.