Rapid onset sodium appetite and orofacial responses to intraoral capsaicin and hypertonic NaCl in the rat.

Sodium appetite reverts from aversive to hedonic the orofacial responses to intraoral hypertonic NaCl in a taste reactivity test (TRT). An electrophysiological-based hypothesis suggests that aversion to salty taste results from oral nociception (e.g.

Lateral parabrachial nucleus and opioid mechanisms of the central nucleus of the amygdala in the control of sodium intake.

Facilitatory and inhibitory mechanisms in the central nucleus of the amygdala (CeA) and the lateral parabrachial nucleus (LPBN), respectively, are important for the control of sodium and water intake. Here we investigated the importance of the opioid mechanisms in the CeA for water and 0.3M NaCl intake in euhydrated or hyperosmotic rats treated with injections of muscimol (GABA agonist) or moxonidine (α adrenergic/imidazoline agonist) into the LPBN, respectively.

Importance of the central nucleus of the amygdala on sodium intake caused by deactivation of lateral parabrachial nucleus.

The lateral parabrachial nucleus (LPBN) and the central nucleus of the amygdala (CeA) are important central areas for the control of sodium appetite. In the present study, we investigated the importance of the facilitatory mechanisms of the CeA on NaCl and water intake produced by the deactivation of LPBN inhibitory mechanisms. Male Holtzman rats (n=7-14) with stainless steel cannulas implanted bilaterally in the CeA and LPBN were used.

Changes in taste reactivity to intra-oral hypertonic NaCl after lateral parabrachial injections of an α2-adrenergic receptor agonist.

Bilateral injections of moxonidine, an α2-adrenoceptor and imidazoline receptor agonist, into the lateral parabrachial nuclei (LPBN) enhance sodium appetite induced by extracellular dehydration. In the present study, we examined whether LPBN moxonidine treatments change taste reactivity to hypertonic NaCl solution administered into the mouth by intra-oral (IO) cannula. Male Holtzman rats prepared with IO and bilateral LPBN cannulas received subcutaneous injections of furosemide (FURO; 10 mg/kg) and captopril (CAP; 5 mg/kg) to induce hypovolemia with mild hypotension and an accompanying salt appetite and thirst before testing the taste reactivity to oral infusions of 0.

Lesions in the central amygdala impair sodium intake induced by the blockade of the lateral parabrachial nucleus.

The blockade of the lateral parabrachial nucleus (LPBN) with the GABAergic receptor agonist muscimol induces strong hypertonic NaCl intake in satiated and normovolemic rats, whereas lesions of the central nucleus of the amygdala (CeA) reduce sodium intake induced by different protocols. In the present study we investigated the effects of bilateral lesions of the CeA on water and 0.3M NaCl intake induced by GABAergic receptor activation with bilateral injections of muscimol into the LPBN in satiated rats.