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Neuronal nicotinic ACh receptors (nAChRs) were studied in the rat hippocampal slice preparation using whole‐cell patch‐clamp recording techniques. Responses to ACh (100 μm) were detected on inhibitory interneurones in the CA1 field of the hippocampus proper and in the dentate gyrus, but not on principal excitatory neurones in either region. The different neuronal types were identified based on their morphology and location. ACh excited interneurones in the hippocampus and dentate gyrus in current‐clamp recordings. In voltage‐clamp recordings, ACh‐activated inward currents were recorded from interneurones in the presence of blockers of synaptic transmission and the muscarinic ACh receptor antagonist atropine. The zero current potential for this response to ACh was near 0 mV. The effect of ACh was mimicked by the nAChR‐selective agonists nicotine (100 μm) and 1,1‐dimethyl‐4‐phenyl‐piperazinium iodide (DMPP, 100 μm). The response to ACh was reversibly antagonized by the neuronal nAChR antagonist mecamylamine (10 μm). The nAChR α7 subunit‐selective antagonists α‐bungarotoxin (100 nm) and methyllycaconitine (10 nm) also inhibited the response to ACh. These observations demonstrate the presence of functional nAChRs on inhibitory interneurones in the rat hippocampus. Thus, a novel mechanism by which ACh can regulate neuronal activity in the hippocampus is revealed.

Abstract:This paper reports on a national study, involving a mixed methods research design comprising a randomised controlled trial, text analysis, student and teacher interviews and lesson observations. It set out to investigate whether contextualised teaching of grammar, linked to the teaching of writing, would improve student outcomes in writing and in metalinguistic understanding. The RCT involved 744 students in 31 schools in the South West and the Midlands of England, and was a blind randomisation study. Classes were randomly allocated to either a comparison or intervention group, after the sample had been matched for teacher linguistic subject knowledge. The statistical data was complemented by three interviews per teacher and three interviews with a focus student in each class, plus three lesson observations in each class, giving a data set of 93 teacher interviews, 93 student interviews and 93 lesson observations. In addition, the final pieces of writing produced for each scheme of work were collected. The statistical results indicate a significant positive effect for the intervention, but they also indicate that this benefit was experienced more strongly by the more able writers in the sample. The regression modelling also indicates that teacher linguistic subject knowledge was a significant mediating factor in the success of the intervention. The qualitative data provides further evidence of the impact of teacher knowledge on how the intervention was implemented and on students' metalinguistic learning. It also reveals that teachers found the explicitness, the use of discussion, and the emphasis on playful experimentation to be the most salient features of the intervention. The study is significant in providing robust evidence for the first time of a positive benefit derived from the teaching of grammar, and signals the potential of a pedagogy for a writing which includes a theorised role for grammar.

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