Laura Bridgeman's brain: an early consideration of functional adaptations in neural development

Procedures and complications in late-nineteenth-century experimental neuroanatomical research exemplified by articles of Henry Herbert Donaldson (1857-1938)

Henry Herbert Donaldson (1857-1938) was a leader in neurological research in the United States for several decades, beginning about 1890. A detailed account of three of his earliest publications shows the neuroanatomical procedures involved in the study of the relation of brain and intelligence during the late-nineteenth-century in America. Two of the articles, published in September 1890 and December 1891, were titled, "Anatomical Observations on the Brain and Several Sense-Organs of the Blind Deaf-Mute, Laura Dewy Bridgman (1829-1889)"; the third, published in August 1892, used the information from the first two to delimit the extent of the visual processing area of the human cortex. Donaldson's procedures included brain cuttings and measures of macroscopic brain structures, histology of cellular structures, attempts to relate macroscopic brain structures with brain functions, data corrections, estimations, comparisons, and statistics. These procedures provide a view of the relative thoroughness, accuracy, and comparability of the various neuroanatomical techniques in use at that time and of Donaldson's implementation of the techniques. Donaldson's brain cutting techniques were much more comparable than his measurement techniques. The latter could be quite precise, but they were fraught with lack of standardized procedures that made corrections and estimations necessary when making data comparisons across studies. Donaldson emphasized these incompatibilities, implying a need for standardization. Statistical procedures were the least thorough and effective. His, and the field's, total complement of statistical techniques consisted of mean and range, which severely limited his ability to make complicated assessments. This limitation was not necessarily supplemented by stringent control group comparisons.

The ontogeny of independent ingestion in mice: or, why won't infant mice feed?

Unlike infant rats, which show deprivation-related ingestion in several different test situations, infant mice appeared to be relatively unwilling to feed independently of suckling until 12 days of age. We tested mouse pups that were deprived (of food, water, suckling, and maternal care) for 1, 7, or 24 hr in ingestive tests in which a milk diet was spread on the floor of their test container (Experiment 1). Pups at 3, 6, and 9 days of age consumed small amounts of the diet and showed little increase in intake when deprivation was increased. In contrast (and like rat pups of all ages), mouse pups 12 and 15 days of age actively ingested the diet and increased their intake with increased deprivation. Six-day-old mouse pups were similarly unwilling to ingest a 5% sucrose solution, though 12-day-old pups showed deprivation-related intake (Experiment 2). Cellular dehydration (produced by hypertonic saline injection), a potent stimulus for ingestion in infant rats, did not stimulate ingestion in mice younger than 12 days of age (Experiment 3). Finally, when ingestion was tested with diet infusions made through oral cannulas, mouse pups at 6 and 9 days of age showed only a slight increase in intake with increased deprivation. However, by 12 days of age, pups' ingestion increased markedly with deprivation (Experiment 4). Thus, mouse pups seem to be very different from rat pups with respect to the early existence of ingestive systems. The neural substrates for the ingestive responses that subserve independent ingestion are only minimally present in infant mice or are somehow inhibited.