Neurophysiological Evaluation of a Customizable µECoG-based Wireless Brain Implant.

The number of implantable bidirectional neural interfaces available for neuroscientific research applications is still limited, despite the rapidly increasing number of customized components. We previously reported on how to translate available components into "ready-to-use" wireless implantable systems utilizing components off-the-shelf (COTS). The aim of the present study was to verify the viability of a micro-electrocorticographic ($\mu $ECoG) device built by this approach. Functionality for both neural recording and stimulation was evaluated in an ovine animal model using acoustic stimuli and cortical electrical stimulation, respectively. We show that auditory evoked responses were reliably recorded in both time and frequency domain and present data that demonstrates the cortical electrical stimulation functionality. The successful recording of neuronal activity suggests that the device can compete with existing implantable systems as a neurotechnological research tool.

The use of ultrasound and computed tomography for the diagnosis of a squamous cell carcinoma of the oesophago-cardial region of the stomach in a rhesus monkey.

A 5-year-old female rhesus macaque (Macaca mulatta) suddenly began suffering from anorexia, dysphagia, vomiting, diarrhoea, and anaemia. Clinical examination and conventional radiography were uneventful. Additionally an ultrasound (US) and computed tomography (CT) were performed which revealed a large tumorous mass in the upper abdomen and a lung metastasis. Using sonographic guidance, a biopsy of the abdominal masse was taken. Histopathological analysis revealed the diagnosis of a squamous cell carcinoma. At autopsy, an advanced gastric carcinoma, which originated from the cardia, was found with infiltration of the retroperitoneum, and metastatic involvement of the mesenterial lymph nodes as well as metastasis in the lung parenchyma. This case illustrates the usefulness of modern non-invasive imaging techniques, including US and CT, in enabling a quick and accurate diagnosis in laboratory animals.