Peripheral nerves in vertebrate systems have been studied for centuries. Nerve anatomy, including the connective tissues that cushion nerves, are well described in the literature. The outer connective tissues, known as the epineurium and perineurium, include a double layer of collagen fibers that form a double helical wrapping that is visible with polarized light microscopy and by other contrast methods. This wrapping is a diagnostic characteristic of nerve tissues. Decades of research into dinosaur bones have produced interesting endocasts of probable brain morphology, but no soft and flexible nerve tissues have been reported from dinosaur remains. In this study we provide evidence of nerve fragments, characterized by a double helical wrapping of collagen fibers, from a Triceratops condyle collected at the Hell Creek Formation, MT. Based on comparison with nerves from an avian model we conclude that these are fragments of nerves that once resided in vivo in Triceratops.

Between 1822 and the late 1830s a highly personal priority dispute was fought between the celebrated surgeon and anatomist Sir Charles Bell and his ex-student Herbert Mayo. The dispute was over the motor and sensory functions of the Vth and VIIth cranial nerves. Over the course of the 1820s and the 1830s, the competing claims of Bell and Mayo were presented in newspapers, journals, and textbooks. But by the time of Bell’s death in 1842, Mayo had been discredited, a seemingly tragic footnote in the history of nervous discovery. And yet, with the benefit of hindsight, Bell’s case was at best disingenuous. His success was not due to any intrinsic scientific merit in his argument, but rather his ability to create a narrative that undermined the credibility of Mayo. However, only when Mayo’s public performances elided with Bell’s descriptions did this ploy succeed. As a result, the dispute illuminates the importance of credibility to the creation of an idealised scientific medical practitioner.

This paper attempts a comprehensive account of ‘fibre medicine’ elaborated by iatromechanists from c. 1700 to c. 1740. Fibre medicine, a medical theory informed by the notion of the fibre, has been neglected by medical historians despite the pivotal role played by the fibre in animal economy. Referring to a wide range of medical fields such as anatomy, physiology, pathology, therapeutics and life sciences, this paper elucidates the ways that the fibre serves as an indispensable concept for iatromechanists to establish their medical theories. This paper also highlights the metaphorical dimension of the fibre as an integral part of fibre medicine. In re-evaluating the concept of the fibre, this paper seeks to redress the neuro-centric view of eighteenth-century medicine, and attempts to locate the fibre body amidst the fundamental shift from humoralism to solidism.

The effects of inhalational anaesthetic agents on renal sympathetic nerve activity (RSNA) were compared in anaesthetized rabbits. Concentrations of 6% desflurane, 1.2% isoflurane, and 2.4% enflurane increased mean RSNA up to 32, 36 and 44% while higher concentrations, of 12, 2.4 and 3.2% depressed it by 42, 83 and 5%, respectively. For halothane RSNA was unchanged up to 0.8% and decreased by 36% at 1.6% concentration. Nitrous oxide increased RSNA up to 28% at 50% concentration. Maximum reductions in mean arterial pressure (MAP) were 60% for both 2.4% isoflurane and 3.2% enflurane, 50% for 12% desflurane and 1.6% halothane, while 70% nitrous oxide increased MAP by 22%. In conclusion, unlike the entirely depressive effects of halothane, the effects of desflurane, isoflurane and enflurane were biphasic involving excitation at lower concentrations and depression of RSNA and a reduction in MAP at higher concentrations. Nitrous oxide caused increases in both RSNA and MAP.