Reflections on Ethics and Humanity in Pediatric Neurology: the Value of Recognizing Ethical Issues in Common Clinical Practice

Our goals in this reflection are to (i) identify the ethical dimensions inherent in any clinical encounter and (ii) bring to the forefront of our pediatric neurology practice the myriad of opportunities to explore and learn from these ethical questions. We highlight specifically Beauchamp and Childress’s principles of biomedical ethics. We use the terms ethics in common clinical practice and an ethical lens to remind people of the ubiquity of ethical situations and the usefulness of using existing ethical principles to analyze and resolve difficult situations in clinical practice. We start with a few common situations with which many of us tend to struggle. We describe what we understand as ethics and how and why developments in technology, novel potential interventions, policies, and societal perspectives challenge us to think about and debate ethical issues. Individual patients are not a singular population; each patient has their own unique life situations, culture, goals, and expectations that need to be considered with a good dose of humanity and humility. We believe that using an ethical lens—by which we mean making an explicit effort to identify and consider these issues openly—will help us to achieve this goal in practice, education, and research.     

Intraoperative subdural low-noise EEG recording of the high frequency oscillation in the somatosensory evoked potential

Objective

The detectability of high frequency oscillations (HFO, >200 Hz) in the intraoperative ECoG is restricted by their low signal-to-noise ratio (SNR). Using the somatosensory evoked HFO, we quantify how HFO detectability can benefit from a custom-made low-noise amplifier (LNA).

Chorea-acanthocytosis presenting as motor neuron disease

Introduction: Chorea‐acanthocytosis (ChAc) is a rare autosomal recessive disease characterized by involuntary movements, seizures, cognitive changes, myopathy, and axonal neuropathy. Methods: We report a patient who presented with gait impairment and dysarthria. Clinical and neurophysiological assessment disclosed upper and lower motor neuron signs suggestive of motor neuron disease (MND). Results: Later observation of involuntary movements prompted further investigation. Acanthocytes were identified, and the patient's chorein level was low. Genetic studies identified a novel double heterozygous mutation of the chorein gene involving an exon‐stop mutation associated with another mutation that can affect the normal splicing of the RNA. Conclusions: We speculate that this genetic mutation could cause the atypical presentation. ChAc should be included in the differential diagnosis of atypical MND. Muscle Nerve, 2012     

The caudal part of the posterior insula of rats participates in the maintenance but not the acquisition of morphine conditioned place preference

The heterogeneous insular cortex plays an interoceptive role in drug addiction by signaling the availability of drugs of abuse. Here, we tested whether the caudal part of the multisensory posterior insula (PI) stores somatosensory‐associated rewarding memories. Using Sprague Dawley rats as subjects, we first established a morphine‐induced conditioned place preference (CPP) paradigm, mainly based on somatic cues. Secondly, an electrolytic lesion of the caudal portion of the PI was carried out before and after the establishment of CPP, respectively. Our data demonstrated that the caudal PI lesions disrupted the maintenance, but not the acquisition of morphine‐induced CPP. Lesion or subtle disruption of the PI had no major impact on locomotor activity. These findings indicate that the caudal portion of the PI might be involved in either the storage or the retrieval of morphine CPP memory.     

Localization of the cannabinoid type‐1 receptor in subcellular astrocyte compartments of mutant mouse hippocampus

Astroglial type‐1 cannabinoid (CB₁) receptors are involved in synaptic transmission, plasticity and behavior by interfering with the so‐called tripartite synapse formed by pre‐ and post‐synaptic neuronal elements and surrounding astrocyte processes. However, little is known concerning the subcellular distribution of astroglial CB₁ receptors. In particular, brain CB₁ receptors are mostly localized at cells' plasmalemma, but recent evidence indicates their functional presence in mitochondrial membranes. Whether CB₁ receptors are present in astroglial mitochondria has remained unknown. To investigate this issue, we included conditional knock‐out mice lacking astroglial CB₁ receptor expression specifically in glial fibrillary acidic protein (GFAP)‐containing astrocytes (GFAP‐CB₁‐KO mice) and also generated genetic rescue mice to re‐express CB₁ receptors exclusively in astrocytes (GFAP‐CB₁‐RS). To better identify astroglial structures by immunoelectron microscopy, global CB₁ knock‐out (CB₁‐KO) mice and wild‐type (CB₁‐WT) littermates were intra‐hippocampally injected with an adeno‐associated virus expressing humanized renilla green fluorescent protein (hrGFP) under the control of human GFAP promoter to generate GFAPhrGFP‐CB₁‐KO and ‐WT mice, respectively. Furthermore, double immunogold (for CB₁) and immunoperoxidase (for GFAP or hrGFP) revealed that CB₁ receptors are present in astroglial mitochondria from different hippocampal regions of CB₁‐WT, GFAP‐CB₁‐RS and GFAPhrGFP‐CB₁‐WT mice. Only non‐specific gold particles were detected in mouse hippocampi lacking CB₁ receptors. Altogether, we demonstrated the existence of a precise molecular architecture of the CB₁ receptor in astrocytes that will have to be taken into account in evaluating the functional activity of cannabinergic signaling at the tripartite synapse.     

Amygdala Inhibitory Circuits Regulate Associative Fear Conditioning

Associative memory formation is essential for an animal’s survival by ensuring adaptive behavioral responses in an ever-changing environment. This is particularly important under conditions of immediate threats such as in fear learning. One of the key brain regions involved in associative fear learning is the amygdala. The basolateral amygdala is the main entry site for sensory information to the amygdala complex, and local plasticity in excitatory basolateral amygdala principal neurons is considered to be crucial for learning of conditioned fear responses. However, activity and plasticity of excitatory circuits are tightly controlled by local inhibitory interneurons in a spatially and temporally defined manner. In this review, we provide an updated view on how distinct interneuron subtypes in the basolateral amygdala contribute to the acquisition and extinction of conditioned fear memories.     

Organization of the pallium in the fire-bellied toad Bombina orientalis. I: Morphology and axonal projection pattern of neurons revealed by intracellular biocytin labeling

The cytoarchitecture and axonal projection pattern of pallial areas was studied in the fire-bellied toad Bombina orientalis by intracellular injection of biocytin into a total of 326 neurons forming 204 clusters. Five pallial regions were identified, differing in morphology and projection pattern of neurons. The rostral pallium receiving the bulk of dorsal thalamic afferents has reciprocal connections with all other pallial areas and projects to the septum, nucleus accumbens, and anterior dorsal striatum. The medial pallium projects bilaterally to the medial pallium, septum, nucleus accumbens, mediocentral amygdala, and hypothalamus and ipsilaterally to the rostral, dorsal, and lateral pallium. The ventral part of the medial pallium is distinguished by efferents to the eminentia thalami and the absence of contralateral projections. The dorsal pallium has only ipsilateral projections running to the rostral, medial, and lateral pallium; septum; nucleus accumbens; and eminentia thalami. The lateral pallium has ipsilateral projections to the olfactory bulbs and to the rostral, medial, dorsal, and ventral pallium. The ventral pallium including the striatopallial transition area (SPTA) has ipsilateral projections to the olfactory bulbs, rostral and lateral pallium, dorsal striatopallidum, vomeronasal amygdala, and hypothalamus. The medial pallium can be tentatively homologized with the mammalian hippocampal formation, the dorsal pallium with allocortical areas, the lateral pallium rostrally with the piriform and caudally with the entorhinal cortex, the ventral pallium with the accessory olfactory amygdala. The rostral pallium, with its projections to the dorsal and ventral striatopallidum, resembles the mammalian frontal cortex.