Auditory cortical areas activated by slow frequency-modulated sounds in mice.

Species-specific vocalizations in mice have frequency-modulated (FM) components slower than the lower limit of FM direction selectivity in the core region of the mouse auditory cortex. To identify cortical areas selective to slow frequency modulation, we investigated tonal responses in the mouse auditory cortex using transcranial flavoprotein fluorescence imaging. For differentiating responses to frequency modulation from those to stimuli at constant frequencies, we focused on transient fluorescence changes after direction reversal of temporally repeated and superimposed FM sweeps. We found that the ultrasonic field (UF) in the belt cortical region selectively responded to the direction reversal. The dorsoposterior field (DP) also responded weakly to the reversal. Regarding the responses in UF, no apparent tonotopic map was found, and the right UF responses were significantly larger in amplitude than the left UF responses. The half-max latency in responses to FM sweeps was shorter in UF compared with that in the primary auditory cortex (A1) or anterior auditory field (AAF). Tracer injection experiments in the functionally identified UF and DP confirmed that these two areas receive afferent inputs from the dorsal part of the medial geniculate nucleus (MG). Calcium imaging of UF neurons stained with fura-2 were performed using a two-photon microscope, and the presence of UF neurons that were selective to both direction and direction reversal of slow frequency modulation was demonstrated. These results strongly suggest a role for UF, and possibly DP, as cortical areas specialized for processing slow frequency modulation in mice

Internal Jugular and Subclavian Vein Thrombosis in a Case of Ovarian Cancer

Central venous catheter insertion and cancer represent some of the important predisposing factors for deep venous thrombosis (DVT). DVT usually develops in the lower extremities, and venous thrombosis of the upper extremities is uncommon. Early diagnosis and treatment of deep venous thrombosis are of importance, because it is a precursor of complications such as pulmonary embolism and postthrombotic syndrome. A 47-year-old woman visited our department with painful swelling on the left side of her neck. Initial examination revealed swelling of the region extending from the left neck to the shoulder without any redness of the overlying skin. Laboratory tests showed a white blood cell count of 5,800/mm3 and an elevated serum C-reactive protein of 4.51 mg/dL. Computed tomography (CT) of the neck revealed a vascular filling defect in the left internal jugular vein to left subclavian vein region, with the venous lumina completely occluded with dense soft tissue. On the basis of the findings, we made the diagnosis of thrombosis of the left internal jugular and left subclavian veins. The patient was begun on treatment with oral rivaroxaban, but the left shoulder pain worsened. She was then admitted to the hospital and treated by balloon thrombectomy and thrombolytic therapy, which led to improvement of the left subclavian venous occlusion. Histopathologic examination of the removed thrombus revealed adenocarcinoma cells, indicating hematogenous dissemination of malignant cells

Subdivisions of MG projecting to the auditory cortex.

<p>(<b>A</b>) Cresyl violet staining of MG. (<b>B</b>) SMI-32 immunostaining of MG in the adjacent section. (<b>C</b>) BDA staining of MG after BDA injection into the cortical area responding to a 25 kHz AM sound within A1. (<b>D</b>) BDA staining of MG after BDA injection into the cortical area responding to a 25 kHz AM sound within AAF. (<b>E</b>) BDA staining of MG after BDA injection into UF. (<b>F</b>) BDA staining of MG after BDA injection into DP. Sections were approximately 3.0 mm posterior to bregma.</p

FM sweep speeds and cortical responses in UF and DP.

<p>(<b>A</b>) Response amplitudes to direction reversal of FM sweeps at a speed between 2 and 120 kHz/s from upward to downward in UF and DP of 6 mice. Insets show image examples. At a speed of 2 or 120 kHz/s, response amplitudes in UF and DP were significantly smaller than the corresponding values obtained at 24 kHz/s (P<0.004, respectively). (<b>B</b>) Response amplitudes to FM direction reversal between 2 and 120 kHz/s from downward to upward in UF and DP of the same 6 mice. At a speed of 2 or 120 kHz/s, response amplitudes in UF and DP were significantly smaller than the corresponding values obtained at 24 kHz/s (P<0.004, respectively).</p