Forgotten memory storage and retrieval in Drosophila.

Inaccessibility of stored memory in ensemble cells through the forgetting process causes animals to be unable to respond to natural recalling cues. While accumulating evidence has demonstrated that reactivating memory-stored cells can switch cells from an inaccessible state to an accessible form and lead to recall of previously learned information, the underlying cellular and molecular mechanisms remain elusive. The current study used Drosophila as a model to demonstrate that the memory of one-trial aversive olfactory conditioning, although inaccessible within a few hours after learning, is stored in KCαß and retrievable after mild retraining. One-trial aversive conditioning triggers protein synthesis to form a long-lasting cellular memory trace, approximately 20 days, via creb in KCαß, and a transient cellular memory trace, approximately one day, via orb in MBON-α3. PPL1-α3 negatively regulates forgotten one-trial conditioning memory retrieval. The current study demonstrated that KCαß, PPL1-α3, and MBON-α3 collaboratively regulate the formation of forgotten one-cycle aversive conditioning memory formation and retrieval.

Entrapment neuropathy of common peroneal nerve by fabella: A case report.

BACKGROUND: Neuropathy of the common peroneal nerve caused by compression by a fabella is an extremely rare form of compression neuropathy. Involving both the superficial and deep peroneal nerves, it usually manifests as either impaired sensation from the lower lateral leg to the top of the foot or drop foot, or as a combination of both. CASE SUMMARY: We report the case of a 58-year-old Asian female who presented with inversion of the right foot during the stance phase of gait without sensory complaints related to the lower leg. Electrodiagnostic testing revealed the neuropathy of the common peroneal nerve at the level of the knee, exclusively affecting the muscular branch of the superficial peroneal nerve. A neuromuscular ultrasound disclosed swelling of the right common peroneal nerve just before it crossed over a large fabella as well as atrophy and fatty infiltration of the right peroneus longus and peroneus brevis muscles. Surgical excision of the fabella and neurolysis were performed. Subsequently, the strength of the right foot evertors improved, but the unsteady gait with occasional falls persisted for nine months after the surgery. Therefore, another procedure was performed to transfer the split posterior tibialis tendon to the peroneus brevis in order to correct the gait. CONCLUSION: This is the first case of neuropathy of the common peroneal nerve caused by compression by a fabella affecting exclusively the muscular branch of the superficial peroneal nerve. Clinicians should be aware of this unusual peripheral neuropathy while evaluating and treating patients with gait disturbance.

Left Atrial Fibroelastoma as a Cause of Stroke: A Case Report.

Cardiac papillary fibroelastoma is a benign and rare primary tumor of the heart that is most frequently located in the aortic or the mitral valves. Papillary fibroelastoma arising from the left atrium is exceedingly rare, comprising less than 7% of all cardiac papillary fibroelastomas. Tumors in this location could be a source of cardioembolic stroke, often in the anterior circulation of the cerebrum. A 66-year-old female presenting with right hemiparesis, central facial palsy, homonymous hemianopia, and dysarthria received intravenous thrombolysis for stroke without apparent improvement. Magnetic resonance imaging of the brain revealed ischemic infarction in the territories of the left middle and posterior cerebral arteries. A tumor with a maximal diameter of 2.3 cm was disclosed during workup for possible cardioembolic stroke with transthoracic echocardiography and computed tomography of the heart. The clinical course was complicated by stroke-in-evolution and hemorrhagic transformation. The patient underwent left atrial tumor excision and left atrium appendage closure. In-patient stroke rehabilitation programs were also initiated after the conditions stabilized. No clinically significant complications developed after the operation. Neurological functions improved and the patient was able to perform most basic daily living activities with some assistance. An exhaustive search for the cause of cardioembolic stroke is paramount, as management strategies may differ from patients with thrombotic stroke.