Browse Items (405 total)

In the mustached bat, combination-sensitive neurons display integrative responses to combinations of acoustic elements in biosonar or social vocalizations. One type of combination-sensitive neuron responds to multiple harmonics of the…

Anecdotal evidence suggests that the foramina of the cribriform plate which transmit cranial nerve I decrease in size with age, but this finding has never been supported with quantitative data. It has also been observed that olfactory function…

The growth of fluorescence imaging technology and the development of sensitive fluorescent retrograde tracers has provided many new approaches for analyzing neuronal circuits. Fluorescent markers provide unparalleled opportunity for combining axonal…

Understanding intraspecific behavioral and dietary variation is critical for assessing primate populations' abilities to persist in habitats characterized by increasing anthropogenic disturbances. While it is evident that some species exhibit…

Locomotor researchers have long known that adult primates employ a unique footfall sequence during walking. Most mammals use lateral sequence (LS) gaits, in which hind foot touchdowns are followed by ipsilateral forefoot touchdowns. In contrast, most…

Despite the importance that concepts of arboreal stability have in theories of primate locomotor evolution, we currently lack measures of balance performance during primate locomotion. We provide the first quantitative data on locomotor stability in…

OBJECTIVES: Relatively long digits are considered to enhance grasping performance in primates. We tested whether growth-related changes in intrinsic hand and foot proportions may have behavioral implications for growing animals, by examining whether…

The importance of locomotion to evolutionary fitness has led to extensive study of primate locomotor behavior, morphology and ecology. Most previous research has focused on adult primates, but in the last few decades, increased attention to locomotor…

OBJECTIVES: Laboratory studies have yielded important insights into primate locomotor mechanics. Nevertheless, laboratory studies fail to capture the range of ecological and structural variation encountered by free-ranging primates. We present…

The whale ear, initially designed for hearing in air, became adapted for hearing underwater in less than ten million years of evolution. This study describes the evolution of underwater hearing in cetaceans, focusing on changes in sound transmission…

Cetaceans (whales, dolphins, and porpoises) have a soft tissue flipper that encases most of the forelimb, and elongated digits with an increased number of phalanges (hyperphalangy). In addition, some cetaceans exhibit a reduction in digit number.…

The forelimb of cetaceans (whales, dolphins, and porpoises) has been radically modified during the limb-to-flipper transition. Extant cetaceans have a soft tissue flipper encasing the manus and acting as a hydrofoil to generate lift. The…

We describe the bony and cartilaginous structures of five fetal skulls of Stenella attenuata (pantropical spotted dolphin) specimens. The specimens represent early fetal life as suggested by the presence of rostral tactile hairs and the beginnings of…

We studied the histology and morphometrics of the hairs of bowhead whales (Balaena mysticetus). These whales are hairless except for two patches of more than 300 hairs on the rostral tip of the lower lip and chin, the rostral tip of the upper lip,…

The nasolacrimal duct (NLD) connects the orbital (often associated with the Deep Anterior Orbital gland: DAOG, a.k.a. Harderian gland) and nasal regions in many tetrapods. Adult cetaceans are usually said to lack an NLD, and there is little agreement…

Few studies exist of the bowhead whale brain and virtually nothing is known about its cortical cytoarchitecture or how it compares to other cetaceans. Bowhead whales are one of the least encephalized cetaceans and occupy a basal phylogenetic position…

Functional studies of skeletal anatomy are predicated on the fundamental assumption that form will follow function. For instance, previous studies have shown that the femora of specialized leaping primates are more robust than those of more…

OBJECTIVE: Cytokine expression is tightly regulated post-transcriptionally but high levels of IL-6 in osteoarthritis (OA) indicate disruption of regulatory mechanisms. ZCCHC6 enzyme is implicated in post-transcriptional regulation of inflammatory…

Perineuronal nets (PNs) are aggregates of extracellular matrix molecules that surround some neurons in the brain. While PNs occur widely across many cortical areas, subcortical PNs are especially associated with motor and auditory systems. The…

The medial geniculate body (MG) receives a large input from the ipsilateral inferior colliculus (IC) and a smaller but substantial input from the contralateral IC. Both crossed and uncrossed inputs comprise a large percentage of glutamatergic cells…

This study examined the output of the central nucleus of the inferior colliculus to the medial geniculate body and other parts of the nervous system in the mustached bat (Pteronotus parnellii). Small deposits of anterograde tracers (horseradish…

What happens to early acquired but later abandoned motor skills? To investigate effects of disuse on early-developing motor skills, we examined crawling in two groups of habitual crawlers (34 6-12-month-old infants and five adults with Uner Tan…

The field of evolutionary developmental biology is broadly focused on identifying the genetic and developmental mechanisms underlying morphological diversity. Connecting the genotype with the phenotype means that evo-devo research often considers a…

Cetaceans are the only mammals to have evolved hyperphalangy, an increase in the number of phalanges beyond the mammalian plesiomorphic condition of three phalanges per digit. In this study, cetaceans were used as a novel model to review previous…

The need to maintain stability on narrow branches is often presented as a major selective force shaping primate morphology, with adaptations to facilitate grasping receiving particular attention. The functional importance of a long and mobile tail…
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