Amino acids related to L-glutamic and y-amino-n-butyric acid have been administered electrophoretically, and by pressure ejection, into the extraneuronal environment of single neurones in the pericruciate cortex of cats anaesthetized with allobarbitone or allobarbitone-urethane. Acidic amino acids related to glutamic acid, particularly N-methyl-D-aspartic acid, excited cortical neurones. Neutral amino acids related to y-amino-n-butyric acid, particularly 3-amino-1-propanesulphonic acid, depressed cortical neurones. Some of the depressants blocked the antidromic invasion of Betz cells by pyramidal volleys. There are no essential differences between the sensitivities of cortical and spinal neurones towards locally administered amino acids. A transmitter function of such amino acids within the mammalian central nervous system is considered unlikely.When ejected electrophoretically from glass micropipettes, many acidic amino acids related to glutamic acid excite neurones in the feline spinal cord (Curtis,

SummaryConsumers of whole foods, such as fruits, demand consistent high quality and seek varieties with enhanced health properties, convenience or novel taste. We have raised the polyphenolic content of apple by genetic engineering of the anthocyanin pathway using the apple transcription factor MYB10. These apples have very high concentrations of foliar, flower and fruit anthocyanins, especially in the fruit peel. Independent lines were examined for impacts on tree growth, photosynthesis and fruit characteristics. Fruit were analysed for changes in metabolite and transcript levels. Fruit were also used in taste trials to study the consumer perception of such a novel apple. No negative taste attributes were associated with the elevated anthocyanins. Modification with this one gene provides near isogenic material and allows us to examine the effects on an established cultivar, with a view to enhancing consumer appeal independently of other fruit qualities.

Summary Acetylcholine in the neocortex is critical for executive function [1–3]. Degeneration of cholinergic neurons in aging and Alzheimer’s Dementia is commonly treated with cholinesterase inhibitors[4–7], however, these are modestly effective and are associated with side-effects, which preclude effective dosing in many patients [8]. Electrical activation of the Nucleus Basalis (NB) of Meynert, the source of neocortical acetylcholine [9,10] provides a potential method of improving cholinergic activation [11,12]. Here we tested whether NB stimulation would improve performance of a working memory task in a non-human primate model. Unexpectedly, intermittent stimulation proved to be most beneficial (60 pulses per second, for 20 seconds every minute), whereas continuous stimulation often impaired performance. Pharmacological experiments confirmed that the effects depended on cholinergic activation. Donepezil, a cholinesterase inhibitor, restored performance in animals impaired by continuous stimulation but did not improve performance further during intermittent stimulation. Intermittent stimulation was rendered ineffective by either nicotinic or muscarinic receptor antagonists. In the months after stimulation began, performance also improved in sessions without stimulation. Our results reveal that intermittent NB stimulation can improve working memory, a finding that has implications for restoring cognitive function in aging and Alzheimer’s Dementia.

4. The significance of these results is discussed in relation to the possible synaptic or non-synaptic action of acetylcholine upon cortical neurones.