Muscarinic Receptors Types 1 and 2 in the Preoptic-Anterior Hypothalamic Areas Regulate Ovulation Unequally in the Rat Oestrous Cycle

Figure 1

A representative diagram of the POA-AHA region shows the site of microinjections and where cell counting was performed. The diagram is based on the Paxinos and Watson’s stereotaxic atlas for the rat brain (a). Representative photomicrographs showed the immunoreactive neurons (brown) for m₂AChR of intact rats on the right side of the POA-AHA, where cells were counted within the central, lateral, and medial portions of the medial preoptic nucleus, magnification 10x (b) and 40x (c); arrowheads show the immunostained (cytoplasmic) neurons in the POA-AHA region. Negative control, magnification 40x (d). Scale bar = 50 μm. See Section 2 for details. MPA, medial preoptic area; MPOM, medial part of medial preoptic nucleus; MPOL, lateral part of medial preoptic nucleus; MPOC, central part of medial preoptic nucleus; PeAV, paraventricular nucleus; 3V, third ventricle; SCh, suprachiasmatic nucleus; SO, supraoptic nucleus; och, optic chiasm.

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