Courtship behaviour reveals temporal regularity is a critical social cue in mouse communication

While animals navigating the real world face a barrage of sensory input, their brains evolved to perceptually compress multidimensional information by selectively extracting the features relevant for survival. Notably, communication signals supporting social interactions in several mammalian species consist of acoustically complex sequences of vocalisations. However, little is known about what information listeners extract from such time-varying sensory streams. Here, we utilise female mice's natural behavioural response to male courtship songs to identify the relevant acoustic dimensions used in their social decisions. We found that females were highly sensitive to disruptions of song temporal regularity and preferentially approached playbacks of intact over rhythmically irregular versions of male songs. In contrast, female behaviour was invariant to manipulations affecting the songs' sequential organisation or the spectro-temporal structure of individual syllables. The results reveal temporal regularity as a key acoustic cue extracted by mammalian listeners from complex vocal sequences during goal-directed social behaviour.

Image-based deep learning reveals the responses of human motor neurons to stress and VCP-related ALS

AIMS

Although morphological attributes of cells and their substructures are recognised readouts of physiological or pathophysiological states, these have been relatively understudied in amyotrophic lateral sclerosis (ALS) research.

METHODS

In this study, we integrate multichannel fluorescence high-content microscopy data with deep learning imaging methods to reveal-directly from unsegmented images-novel neurite-associated morphological perturbations associated with (ALS-causing) VCP-mutant human motor neurons (MNs).

RESULTS

Surprisingly, we reveal that previously unrecognised disease-relevant information is withheld in broadly used and often considered 'generic' biological markers of nuclei (DAPI) and neurons ( β III-tubulin). Additionally, we identify changes within the information content of ALS-related RNA binding protein (RBP) immunofluorescence imaging that is captured in VCP-mutant MN cultures. Furthermore, by analysing MN cultures exposed to different extrinsic stressors, we show that heat stress recapitulates key aspects of ALS.

CONCLUSIONS

Our study therefore reveals disease-relevant information contained in a range of both generic and more specific fluorescent markers and establishes the use of image-based deep learning methods for rapid, automated and unbiased identification of biological hypotheses.

Heterotransplantation of a human oligoastrocytoma into nude mice: difference in tumour growth between males and females

A human oligodendroglial tumour cell line was established in the nude mouse from a mixed oligoastrocytoma. This cell line was identified by immunoperoxidase screening for glial fibrillary acid protein (GFAP) and Leu-7, by electron microscopy, by its growth behaviour, and by radioreceptor assays for oestrogen, progestogen and androgen. At the first heterotransplantation, the tumour grew in the female but not in the male mice. GFAP-positive cells were much less abundant than in the initial tumour, although Leu-7 positive cells were plentiful. Growth curves were biphasic, and the tumours contained both oestrogen and androgen receptors. After three successive heterotransplantations in female mice, GFAP-negative, Leu-7-positive tumours with the cytological features of an oligodendroglioma were obtained. In contrast to those of the first heterotransplantation, the growth curves showed a longer latency and a single growth phase. The tumours contained both progestogen and androgen receptors but lacked oestrogen receptor. The 5th heterotransplantation in male mice exhibited rapid growth, similar to the three previous heterotransplantations in the female mice. The growth observed solely in the female mice at the first heterotransplantation was thought to derive from the hormonal status of the host. The presence of hormone receptors in the tumours at the first heterotransplantation lent support to this idea. There was no further influence of the sex of the host on tumour growth once the oligodendroglial line was established. The establishment and the development of oligodendrocytes may result from differentiation of transitory cells intermediate between astrocytes and oligodendrocytes. The effect of host-sex on the development of oligodendrocytes points to a new facet of the differentiation of CNS glial cells.

Influence of host sex on the growth of a human glioblastoma line in athymic mice

Glioblastomas are generally thought to be more common in men than in women. In order to investigate the hormone-dependence of these tumours, we established a human glioblastoma line in athymic mice. The tumour cell type was characterized using immunocytochemical methods. The influence of host sex on growth was evaluated, and hormone receptors were characterized biochemically. The histological features of the initial tumour were conserved in the hetero-transplanted tumours, which consisted of vimentin and GFAP immunoreactive astrocytes. There was a highly significant difference in tumour growth between the two sexes (P less than 0.01). In the male mice, tumours were from 2.5 to 10 times larger than in the females, the latency periods were 30% shorter, and the growth phases were characterized by periods of slow or zero growth. In addition, androgen and oestrogen receptors were detected at low levels (80-270 fmol/g tumour) in the heterotransplanted tumours especially in the males. The fact that the male tumour growth profiles resembled those of some hormone-dependent lines, and that androgen receptors were found preferentially in the male rather than in female tumours would tend to indicate that there is a hormonal influence on the growth of the heterotransplanted tumours. These results provide further evidence for an influence of sex-steroid hormones on the growth of glioblastomas.

Cytosolic and nuclear sex steroid receptors in meningioma

To determine the nature of the hormone dependency of meningioma, particularly whether progestin receptor (PR) and tumor growth are estrogen-dependent, we measured the cytosol estrogen receptor (ER) and PR separately by an exchange assay with [3H]R 2858 (for ER) and [3H]RU 27987 (for PR) in 21 meningiomas. We correlated these receptors with age, plasma estradiol and progesterone concentrations, histological subtypes, clinical data such as uterine fibromas, and finally preoperative glucocorticoid therapy. ER was detected at low levels in the cytosol and in the nucleus of a few tumors whereas PR was found in 20 of 21 cases at moderate to high levels, usually with higher concentrations in the cytosol than in the nucleus. No clear relation could be drawn between either cytosol or nuclear ER and PR levels and estradiol and progesterone plasma concentrations, or with the other parameters. On the contrary, a clear correlation could be drawn between cytosolic PR and androgen receptor (AR) concentrations (measured with [3H]R 1881 in the presence of triamcinolone acetonide), leading to several hypotheses of hormonal regulation in meningioma.