カエル味覚器内の副交感性神経終末の存在について

An investigation was made of the precise origin of the efferent nerve terminals in the fungiform papillae of the bullfrog\u27s tongue. Some axonal enlargements originate from the parasympathetic postganglionic neurons in the glossopharyngeal nerve. Axonal enlargements containing large dense-cored vesicles (100-120 nm in diameter) and small, clear synaptic vesicles (50-60 nm in diameter) were in close contact with the supporting cell in the taste disk. These results seem to provide morphological evidence for the existence of an efferent control system in the taste disk of the bullfrog

カエル舌咽神経のNa塩味覚刺激に対する相動性応答の性質

The frog glossopharyngeal nerve responds transiently to relatively high concentrations of Na-salts after rinsing the tongue with 1mM NaCl. In the present study, the properties of the phasic responses of the frog glossopharyngeal nerve to Na-salts were investigated. Cross-adaptation experiments between NaCl and LiCl indicate that NaCl and LiCl were very similar to each other. This is in agreement with the fact that LiCl also gives rise to a good salty in humans. The order of effectiveness of Na-salts was NaCl≒Na acetate (NaAc)>Na gluconate (NaGlu). We found that gluconate^- weakly inhibited the phasic response to Na^+. The modulation by gluconate^-was specific to the phasic response to Na^+, because NaAc and NaGlu have a similar effect on phasic responses to quinine-HCl. Amiloride, an epithelial sodium channel broker, did not affect phasic responses to NaCl at 1.5 min after application of amiloride to the tongue, suggesting that amiloride-sensitive Na^+ channels in the apical membrane are not involved in phasic reponses to Na-salts in the frog glossopharyngeal nerve. Unitary impulses from single sensory units were recorded using the suction electrode method (Kitada, 1978). The latency between onset of stimulation and appearance of the first impulses elicited by 100mM NaCl was average 100 msec. Since the time required for antidromic conduction from the impulse initiation site to the recording site was very short, about 2.4 msec (Sato et al., 1987), it was suggested that the latency obtained here was close to the time between the arrival of the chemical stimulus to the apical membrane and the first impulse in taste fibers. The long latency of impulses in responses to NaCl suggests that cation-channels in the apical membrane are not involved in NaCl taste reception responsible for the phasic response

Maintenance of chorda tympani salt taste responses after nerve transection in rats

To determine whether neurophysiological responses to salts change differentially or in parallel during long recording sessions after nerve transection, we recorded from the cut chorda tympani nerve in rats while stimulating the anterior tongue with NaCl, LiCl, NH4Cl and KCl. In nerve preparations that were not disturbed once recording began, responses were maintained at or above initial magnitudes for an average of 10 h and declined to 50% by 15 h. If the cut end of the nerve was redissected when responses began to decline, stable responses were maintained for an average of 12 h, and did not decline to 50% until 21-24 h. In all rats, responses to the 4 salts altered in parallel for at least 19 h. However in two animals, after 23 h the responses to NaCl and LiCl declined disproportionately, relative to NH4Cl and KCl. Therefore in the course of a typical recording session, i.e. 10-12 h, stable taste responses are obtained and even when responses begin to decline after longer periods, response magnitudes to 4 salts alter in parallel. This indicates that receptor membrane components interacting with specific monochloride salts do not degenerate differentially during the first 19 h after nerve cut.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24783/1/0000207.pd

Diffuse large B-cell lymphoma presenting with neurolymphomatosis and intravascular lymphoma: a unique autopsy case with diverse neurological symptoms

Abstract A 78-year-old Japanese male noticed a difficulty in the beginning of standing up, followed by 7a progressive numbness of extremities with pain, Bell’s palsy, dysarthria, and difficulty in swallowing. A clinician had suspected cancer of unknown primary origin, accompanied by the diverse and elusive neurological symptoms, likely presenting as painful mononeuropathy simplex and cranial neuropathy. He developed dysbasia over weeks and died 1 month after the symptom onset. At autopsy, an ill-defined large and soft tumor mass in the right lobe of the liver with direct invasion into the right adrenal gland was observed. The left adrenal gland or right iliopsoas muscle was also involved. Microscopic findings showed a monotonous proliferation of medium-sized to large atypical lymphoid cells, which were diffusely positive for CD20 in immunohistochemistry, consistent with diffuse large B-cell lymphoma (DLBL). Furthermore, the lymphoma cells aggressively infiltrated endoneurial and subperineurial spaces not only in the peripheral nerves and plexuses, but partly in the spinal nerve roots, and intravascular spaces in various tissues. Therefore, systemic lymphoma (DLBL) complicated with neurolymphomatosis (NL) and intravascular lymphoma (IVL) was diagnosed. Very early diagnosis and treatment are necessary for the NL patients with poor prognosis. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5862472377020448.</p