{'fraction_non_alphanumeric': 0.037753222836095765, 'fraction_numerical': 0.010128913443830571, 'mean_word_length': 4.632124352331606, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Puzzling Out Smells

The mammalian sense of smell discriminates an incredible diversity of odors. In the olfactory bulb, each type of odor receptor links up to unique glomeruli that relay the signals up for higher processing in the brain. Immediately after birth, however, the connections from nasal epithelium to the olfactory bulb run helter-skelter. Zou et al. have now analyzed the process of refinement using mice in which expression of two specific odorant receptors has been marked. Elimination of odoriferous input during specific times of development stalled an intrinsic process by which the inputs from multiple odorant receptors to a given glomerulus are sorted out to produce a mature glomerulus that responds to only one type of odorant signal. Thus, the experience of smell during a critical period is required for maturation of the odorant interpretation system. D.-J. Zou, P. Feinstein, A. L. Rivers, G. A. Mathews, A. Kim, C. A. Greer, P. Mombaerts, S. Firestein, Postnatal refinement of peripheral olfactory projections. Science 304, 1976-1979. [Abstract] [Full Text]