Mouse nerve growth factor: a rapid isolation procedure for the alpha and gamma subunits.

A rapid method for isolating the α and γ subunits of mouse submaxillary gland nerve growth factor, as by-products of the commonly used Bocchini-Angeletti (2.5 S) procedure, has been devised. Approximately 40 mg of each subunit is obtained from 400 pairs of adult glands. The subunits isolated in this fashion are indistinguishable from those obtained from the homogeneous 7 S complex as judged by gel electrophoresis or their association-dissociation behavior.     

Generating precise mechanical stimuli and recording chordotonal organ discharge patterns using a microcomputer

A computer-controlled system for the investigation of the responseproperties of the tibio-femoral chordotonal organ in the locustis described. The computer is used to generate small amplitudesinusoidal movements of the tibia via a small servo-controlledmotor. The resulting response recorded via a suction electrodeis simultaneously detected, processed and stored on disk. Fullconstructional details for all hardware required are given.The software, developed for a BBC microcomputer, in additionto controlling all the hardware, has graphics and analysis routinesenabling the operator to display and manipulate the stored data.     

Computed tomography in the investigation of dementia.

To assess the value of computed tomography in investigating patients with dementia, 500 consecutive patients presenting with a provisional clinical diagnosis of dementia of recent onset were reviewed and the results analysed in a computer. Most patients had either cerebral atrophy or infarction, but 82 patients had a normal scan and 42 others had tumours. More than 10% of all patients, including 5% with no other symptoms or signs, had a treatable lesion. Various associated symptoms and signs were useful pointers to such a treatable lesion and clearly indicated computed tomography. Accurate diagnosis is the cornerstone of proper management, and if a few patients with treatable lesions can be identified then the benefits to all concerned may be incalculable.     

Evidence supporting the microbiota–gut–brain axis in a songbird

Recent research in mammals supports a link between cognitive ability and the gut microbiome, but little is known about this relationship in other taxa. In a captive population of 38 zebra finches (Taeniopygia guttata), we quantified performance on cognitive tasks measuring learning and memory. We sampled the gut microbiome via cloacal swab and quantified bacterial alpha and beta diversity. Performance on cognitive tasks related to beta diversity but not alpha diversity. We then identified differentially abundant genera influential in the beta diversity differences among cognitive performance categories. Though correlational, this study provides some of the first evidence of an avian microbiota–gut–brain axis, building foundations for future microbiome research in wild populations and during host development.     

Functional analysis of RXLR effectors from the New Zealand kauri dieback pathogen Phytophthora agathidicida

New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms. From the P. agathidicida genome, we defined and analysed a set of RXLR effectors, a class of proteins that typically have important roles in suppressing or activating the plant immune system. RXLRs were screened for their ability to activate or suppress the Nicotiana plant immune system using Agrobacterium tumefaciens transient transformation assays. Nine P. agathidicida RXLRs triggered cell death or suppressed plant immunity in Nicotiana, of which three were expressed in kauri. For the most highly expressed, P. agathidicida (Pa) RXLR24, candidate cognate immune receptors associated with cell death were identified in Nicotiana benthamiana using RNA silencing-based approaches. Our results show that RXLRs of a pathogen of gymnosperms can interact with the immune system of an angiosperm species. This study provides an important foundation for studying the molecular basis of plant–pathogen interactions in gymnosperm forest trees, including kauri.