Estudo morfométrico do canal do hipoglosso

The hypoglossal nerve (HN) is responsible for the intrinsic and extrinsic muscles of the tongue. Knowledge of this is extremely important because this nerve is responsible for tongue movement. HN paralysis can be associated to the disease itself in various zones in which the NH travels, mainly the hypoglossal canal (HC). Variations in shape of the hypoglossal canal have been pointed to as the cause of HN paralysis in several studies. Four hundred dried intact human skulls without sex or race identification, belonging to the Discipline of Anatomy of ICTSJC – UNESP were studied. Each canal was classified into types: type I (without division in the HC), type II (HC with low bone spike), type III (HC more than two projections bone), type IV (presence of complete bony bridge without dividing HC into two distinct canals) and type V (presence of bone bridge by dividing into two HC canals). HC was found in 100% of skulls studied in both side. Regarding types, we found 538 (67.25%) hypoglossal canal of type I (34%, right side and 33.25%, left side), 108 (13.5%) of type II (7.38%, right side, and 6.13%, left side), 60 (7.5%) hypoglossal canal of type III (3.5%, right side and 4.0%, left side) 84 (10.5%) of type IV (4.75%, right side and 5.75%, left side) and 5 (0.63%) of the type V (0.13%, right side and 0.5%, left side). We found 5 (0,63%) different HC and classified ourselves in type VI, VII and VIII. The average angle was 51,3º on right side and 50,25º on left side. Detailed knowledge of the anatomy of the CH supports professionals in interventions of bloody skull base and also in giving the correct diagnosis of the probable causes of paralysis of the hypoglossal nerve

Short-term sustained hypoxia induces changes in the coupling of sympathetic and respiratory activities in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sympatho-excitation during chemoreflex active expiration is mediated by L-glutamate in the RVLM/Bötzinger complex of rats

The involvement of glutamatergic neurotransmission in the rostral ventrolateral medulla/Bötzinger/pre-Bötzinger complexes (RVLM/BötC/pre-BötC) on the respiratory modulation of sympathoexcitatory response to peripheral chemoreflex activation (chemoreflex) was evaluated in the working heart-brain stem preparation of juvenile rats. We identified different types of baro- and chemosensitive presympathetic and respiratory neurons intermingled within the RVLM/BötC/pre-BötC. Bilateral microinjections of kynurenic acid (KYN) into the rostral aspect of RVLM (RVLM/BötC) produced an additional increase in frequency of the phrenic nerve (PN: 0.38 ± 0.02 vs. 1 ± 0.08 Hz; P < 0.05; n = 18) and hypoglossal (HN) inspiratory response (41 ± 2 vs. 82 ± 2%; P < 0.05; n = 8), but decreased postinspiratory (35 ± 3 vs. 12 ± 2%; P < 0.05) and late-expiratory (24 ± 4 vs. 2 ±1%; P < 0.05; n = 5) abdominal (AbN) responses to chemoreflex. Likewise, expiratory vagal (cVN; 67 ± 6 vs. 40 ± 2%; P < 0.05; n = 5) and expiratory component of sympathoexcitatory (77 ± 8 vs. 26 ± 5%; P < 0.05; n = 18) responses to chemoreflex were reduced after KYN microinjections into RVLM/BötC. KYN microinjected into the caudal aspect of the RVLM (RVLM/pre-BötC; n = 16) abolished inspiratory responses [PN (n = 16) and HN (n = 6)], and no changes in magnitude of sympathoexcitatory (n = 16) and expiratory (AbN and cVN; n = 10) responses to chemoreflex, producing similar and phase-locked vagal, abdominal, and sympathetic responses. We conclude that in relation to chemoreflex activation 1) ionotropic glutamate receptors in RVLM/BötC and RVLM/pre-BötC are pivotal to expiratory and inspiratory responses, respectively; and 2) activation of ionotropic glutamate receptors in RVLM/BötC is essential to the coupling of active expiration and sympathoexcitatory response.