An investigation of the effect of tacrine and physostigmine on spatial working memory deficits in the olfactory bulbectomised rat.

The olfactory bulbectomised (OB) rat is being increasingly used as a model of impaired learning and mnemonic functioning. In this study the model has been utilised to determine the effect of the acetylcholinesterase inhibiting compounds tacrine and physostigmine on spatial working memory deficits associated with the OB rat. One-hundred and twenty male rats were randomly allocated to OB or sham operated groups and received chronic i.p. treatment with either saline, physostigmine (0.1 mg/kg) or tacrine (0.1 and 0.3 mg/kg). Two weeks after beginning treatment animals were tested on the Morris water maze and open field test. The results indicated that the OB surgery was associated with spatial working memory disturbances that were effectively attenuated with both doses of tacrine, but not physostigmine. Increased hyperactivity and defecation was observed in OB animals in the Open-field test, however, these changes were not ameliorated by either drug treatment. The ability for tacrine but not physostigmine to attenuate OB cognitive deficits may be associated with the different half-life of these compounds. This study provides further support for the use of the OB rat as a drug discovery model for the investigation of novel therapeutic compounds that target the cholinergic system.

OMENS-Plus: analysis of craniofacial and extracraniofacial anomalies in hemifacial microsomia.

This review of 121 patients with hemifacial microsomia (HFM) revealed that 67 (55.4%) had extracraniofacial anomalies. Sixteen patients (13%) had one extracraniofacial anomaly and 51 patients (42.4%) had anomalies of multiple organ systems. There was no gender or side predominance in the cohort with the HFM "expanded spectrum." Central nervous system (CNS), cardiac, and skeletal anomalies were "associated" (i.e., had frequencies of 10% or more). Pulmonary, gastrointestinal, and renal deformities were equivocally associated. Statistical analysis indicated significant associations between several orbital, mandibular, ear, neural, and soft tissue (OMENS) variables and extracraniofacial anomalies. Patients with extracraniofacial structural defects had higher OMENS grades for individual craniofacial anatomic categories. Furthermore, patients with expanded spectrum had higher total OMENS scores. The frequency of cardiac anomalies (26%) supports the model of neural crest involvement in the pathogenesis of both hemifacial microsomia and conotruncal defects. The majority of the heart defects in this study were of either the outflow or septal type. We propose that the OMENS classification system for craniofacial anomalies of HFM be expanded to OMENS-Plus (+) to designate the presence of associated extracraniofacial anomalies.