Differential Regulation of Innate and Learned Behavior by Creb1/Crh-1 in Caenorhabditis elegans.

Memory formation is crucial for the survival of animals. Here, we study the effect of different crh-1 [Caenorhabditis elegans homolog of mammalian cAMP response element binding protein 1 (CREB1)] isoforms on the ability of C. elegans to form long-term memory (LTM). Null mutants in creb1/crh-1 are defective in LTM formation across phyla. We show that a specific isoform of CREB1/CRH-1, CRH-1e, is primarily responsible for memory related functions of the transcription factor in C. elegans Silencing of CRH-1e-expressing neurons during training for LTM formation abolishes the LTM of the animal. Further, CRH-1e expression in RIM neurons is sufficient to rescue LTM defects of creb1/crh-1-null mutants. We go on to show that apart from being LTM defective, creb1/crh-1-null animals show defects in innate chemotaxis behavior. We further characterize the amino acids K247 and K266 as responsible for the LTM related functions of CREB1/CRH-1 while being dispensable for its innate chemotaxis behavior. These findings provide insight into the spatial and temporal workings of a crucial transcription factor that can be further exploited to find CREB1 targets involved in the process of memory formation.SIGNIFICANCE STATEMENT This study elucidates the role of a specific isoform of CREB1/CRH-1, CRH-1e, in Caenorhabditis elegans memory formation and chemosensation. Removal of this single isoform of creb1/crh-1 shows defects in long-term memory formation in the animal and expression of CREB1/CRH-1e in a single pair of neurons is sufficient to rescue the memory defects seen in the mutant animals. We further show that two specific amino acids of CRH-1 are required for the process of memory formation in the animal.

Full mouth rehabilitation of a patient with amelogenesis imperfecta: a case report.

Amelogenesis imperfecta (AI) is a hereditary disorder expressing a group of conditions which cause developmental alterations in the structure of enamel. This disorder has an adverse impact on oral health and also hampers the quality of life of the individual causing physiologic problems. The treatment of such patients would not only upgrade their quality-of-life, but also improve their self-esteem. The correction of such severely worn out dentition may require extensive restorative treatment to achieve appropriate results. It is important to identify the factors that contribute to the excessive wear and loss of vertical dimension. The correction of the defects has to be done without violating the biologic or mechanical principles. Full mouth rehabilitation in such patients improves esthetics, function and comfort. The following case report presents a systematic approach in rehabilitating a case of AI hypoplastic type using full mouth metal reinforced porcelain restorations.

Inflammatory pseudotumour of the lung.

Inflammatory pseudotumours of the lungs have rarely been reported. These have been described as a benign entity of unknown origin and are often locally invasive requiring extensive pulmonary resection. We present a 12-year-old boy with fever and massive haemoptysis who was found to have a well defined left-sided paracardiac mass lesion on chest X-ray and CT scan thorax. A CT-guided fine needle aspiration cytology was reported as inflammatory pseudotumour. As a result of recurrent episodes of massive haemoptysis during admission the child underwent an emergency left posterolateral thoracotomy and excision of the mass along with a left pneumonectomy. The biopsy of the mass was conclusive. Postoperatively the child was ventilated over night and was extubated the next day. He has been doing well on follow-up. Based on our case report and on other similar reports it would appear that the primary treatment of inflammatory pseudotumors of the lung is surgical. Complete resection is the key to prevent recurrence and the prognosis is excellent following surgery.