bluuebunny/crossref_metadata_2025_split huggingface dataset:
General Organization and Parallel Pathways in the Somatosensory System
Authors: Mo Christina 
Published: November 2023

Abstract
The processing of somatosensory stimuli from periphery to cortex occurs along ascending neural channels, segregated by their stimulus features and locations throughout the head and body. This chapter describes the 2 main parallel pathways in humans and discusses further details at the level of thalamus and cortex using animal models. Research using animal models has focused on the body part specialized for each species, which limits generalizations to mammalian somatosensory processing. Primate work has focused on neural recordings in the monkey using hand stimuli, while understanding the organization in rodents has generally been investigated in the whisker system. In both species, integration of the pathways occurs in primary somatosensory cortex and up the cortical hierarchy, despite anatomically parallel inputs to cortex. Anatomical tracing across multiple synapses, combined with detailed functional classification of the projections, will be key to understanding the processing of such diverse sensory inputs.
Thalamic Control of Motor Cortical Synchrony
Authors: Nashef Abdulraheem , Prut Yifat 
Published: November 2023

Abstract
The cerebellar-recipient motor thalamus is a critical interface between cerebellar output and the motor cortical areas. Axons from the deep cerebellar nuclei make potent synaptic contacts with thalamic neurons, which in turn send thalamocortical axons to innervate large areas of the motor and premotor cortex. The convergent/divergent structure of this system puts the cerebellar thalamus in a unique position to extract information from incoming cerebellar signals and forward this processed output to the motor cortex, where it affects the planning and execution of voluntary movements. However, the mechanisms harnessed by the cerebellar thalamus to achieve this task remain unclear. This chapter reviews accumulating evidence suggesting that the cerebellar thalamus regulates motor cortical activity by influencing both inhibitory and excitatory cortical neurons. Through the dynamic and task-dependent control of excitation and inhibition, thalamocortical inputs effectively control the local and global coordinated activity of motor cortical cells that hence affect the timing and coordination of voluntary movements.
Feedforward and Feedback Connections
Authors: Angelucci Alessandra , Petreanu Leopoldo 
Published: November 2023

Abstract
The mammalian sensory neocortex consists of hierarchically organized areas reciprocally connected via inter-areal feedforward (FF) and feedback (FB) pathways. As information ascends through this cortical hierarchy, via FF connections, neuronal receptive fields (RFs) become tuned to increasingly complex stimulus features, and an increasingly abstract representation of the sensory inputs is achieved. FF connections are reciprocated by FB connections from higher-order areas to lower-order areas. Reciprocal FF-FB connections between cortical areas are found throughout the neocortex of all mammalian species, suggesting that they carry out fundamental computations. This chapter reviews data primarily from primate, cat, and mouse on the anatomical organization, functional connectivity, synaptic physiology, and functional impact of FF and FB pathways, with a particular focus on the visual system, where these connections have been mostly studied. The picture that emerges from these studies is one in which both FF and FB connections show a high degree of anatomical specificity with respect to areas, layers, and cell types they interconnect. This specificity serves to parse FF and FB connections into specialized processing streams. Within each stream, FF connections drive sensory responses in higher-order areas and mediate the complexification of RFs along the cortical hierarchy; instead, FB connections provide stream-specific top-down modulations of lower-order areas reflecting sensory context, predictions, and the internal states of the organism. These complementary functions of FF and FB connections result from differences in their visuotopic extent, targeted cell types, synaptic physiology, and location of their synaptic contacts on the postsynaptic neurons.
Modular Architecture of Layer 1 as a Template for the Organization of the Mouse Distributed Hierarchical Visual Network
Authors: Burkhalter Andreas 
Published: November 2023

Abstract
The shift in the understanding of the visual system, as a hierarchical network for constructing increasingly complex receptive fields, to one in which bottom-up feedforward and top-down feedback processing play complementary roles, has put the spotlight on the cortical “feedback” layer 1. This chapter reviews evidence that in primary visual cortex of mice, rats, and macaque monkey, layer 1 contains M2 muscarinic acetylcholine receptor-positive patches and M2-negative interpatches. The modular expression of this marker provides a template for dividing the thalamic and cortical networks into distinct but overlapping ventral, dorsal lateral, and dorsal medial subnetworks. This tripartite framework extends the earlier binary model, and suggests that the ventral stream is specialized for object recognition, whereas the lateral and medial dorsal subnetworks process heading direction and predict optic flow based on motor information during navigation, respectively.
Predictive Coding
Authors: Shipp Stewart , Friston Karl 
Published: November 2023

Abstract
Predictive coding algorithms specify reciprocal message passing between hierarchical levels of a modular computation; likewise, the cerebral cortex can be characterized as a hierarchical arrangement of areas communicating via reciprocal forward and backward pathways. If the former is a model for the latter, it imposes several constraints over the micro- and macro-structure of pathways linking cortical areas, for example: which classes of neuron, with identified computational roles, make direct contact with each other; the topographic specificity of reciprocal connections, as realized through convergent and divergent connectivity; and the relative incidence of “manifold” processing (axonal distribution to multiple targets) in forward and backward connections. These issues are examined with reference to the visual system in mouse and monkey, with the conclusion that the mainstream organization of connectivity is largely compliant. Judicious expansion of the theoretical framework can accommodate some anomalous aspects of connectivity, and predict elements yet to be investigated experimentally.
Thalamic Bases of Goal-Directed Behaviors
Authors: Wolff Mathieu 
Published: November 2023

Abstract
Thalamic nuclei have been increasingly scrutinized over the past few years in various fields ranging from sensory-motor to cognitive functions. An emerging aspect of their functional contribution is that they appear to play highly integrative roles in largely distributed neural circuits. This chapter aims to document the contribution of the thalamus to flexible and adaptive behaviors that are integral to decision-making. These so-called goal-directed behaviors can be conveniently examined in animal models in the laboratory to examine their neural underpinnings. Multiple thalamic nuclei appear to support goal-directed behaviors with specific and complementary contributions. In particular, thalamic nuclei interact with both prefrontal areas and basal ganglia to initiate adaptive actions, attend to relevant environmental signals, and ultimately shape mental representations. Integrating computational approaches with a systematic input-output mapping of thalamic nuclei may be key to reveal the functional principles that govern thalamic functions. This is most important to advance conceptual and mechanical understanding of multiple mental conditions associated with brain-wide dysconnectivity.
Critical Period Plasticity and Development of Binocular Vision
Authors: Cang Jianhua , Ribic Adema 
Published: November 2023

Abstract
The cortical circuits underlying binocular vision are established in an experience-dependent manner during critical periods of early life. Binocular development and critical period plasticity are most commonly studied by examining changes of ocular dominance in response to visual deprivation during early postnatal development (i.e., ocular dominance plasticity). These studies have identified the vital role of balanced visual input in structural and functional development of the primary visual cortex (V1), as well as molecular, synaptic, and circuit mechanisms that regulate the onset and closure of the critical period for ocular dominance plasticity. Binocular V1 neurons are further tuned to similar orientations through the 2 eyes and are selective for certain disparities between the 2 eyes’ input, a property important for computing stereoscopic depth. Interocular matching of orientation preference and development of disparity selectivity require normal visual experience and take place in time windows that are similar but not identical to the critical period of ocular dominance plasticity. This chapter reviews current understandings of the developmental mechanisms underlying all 3 measures of binocular vision. The authors focus the discussion on general concepts of binocular development, as well as significant gaps and opportunities for future studies.
Development and Plasticity of Feature Selectivity
Authors: Griswold Sophie V. , Van Hooser Stephen D. 
Published: November 2023

Abstract
The sensory detectors of the visual system are built through mechanisms that depend on the visual experience of the individual animal, and through mechanisms that have evolved over the eons of evolution but do not depend on the experience of the individual animal. Given the abilities of modern deep-learning systems to learn from examples, one might imagine that a large fraction of the visual system might be built purely by learning through example, but a majority of the receptive field properties are initially formed through molecular cues and activity-dependent plasticity that depends only on spontaneous activity. Even some features that require that the individual animal have visual experience, such as the development of direction selectivity in carnivores and primates, are largely seeded at the onset of visual experience, and properties like direction preference angle are not very malleable. This chapter focuses on receptive field properties except for binocular responses, which are the subject of Chapter 51 in this volume.
Modeling Thalamocortical Oscillations
Authors: Golden Ryan , Bazhenov Maxim 
Published: November 2023

Abstract
The dynamics of the thalamocortical system are characterized by a diverse set of oscillatory activities with dominant frequencies ranging from below 0.01 Hz to above 600 Hz. Many of these activities, such as ripple (&gt;80 Hz), gamma (30–60 Hz) and infra-slow (0.01–0.2 Hz) oscillations, can be observed across a wide array of behavioral states, while others, such as the slow (0.3–1 Hz), delta (1–4 Hz), and spindle (9–15 Hz) oscillations, are stereotypical of certain stages of sleep. Each of these oscillations has been implicated in various behavioral and cognitive phenomena, particularly arousal/vigilance, memory, and attention. This chapter briefly discusses the relevant intrinsic (i.e., cellular) and extrinsic (i.e., network) properties that generate the 6 above oscillations, as well as the cognitive and behavioral functions they serve.
Control of Thalamocortical Signaling Through Spike Timing and Synchrony
Authors: Stanley Garrett B. 
Published: November 2023

Abstract
The sensory thalamus has long been described as a “gate” of sensory signaling from periphery to cortex. Underlying this gating is a range of intrinsic biophysical properties of the thalamic neurons themselves, but also the way in which the thalamic neurons project and synapse onto their cortical targets. Disynaptic inhibition at the thalamocortical junction is a particularly prominent motif that is thought to play a major role in regulating signaling through sensitivity to timing and synchrony of thalamic inputs to cortex, establishing what is often referred to as a “window of opportunity” for sensory signaling. This mechanism is ubiquitous in the thalamocortical circuit and is a computational mechanism that subserves feature selectivity and shapes perception. This chapter briefly describes the relevant anatomy, discusses intracellular studies that have captured the nature of the excitatory/inhibitory interaction, and describes functional studies that illustrate how this shapes selectivity and controls information flow in sensory pathways.
Thalamic Dysconnectivity Across the Schizophrenia Illness Course and Psychosis Spectrum
Authors: Abram Samantha V. , Spiro Caleb M. , Ford Judith M. 
Published: November 2023

Abstract
Abnormalities in thalamocortical connectivity are a robust feature of schizophrenia. These abnormalities are reflected by both reduced connectivity between the thalamus and prefrontal and cerebellar areas, as well as increased connectivity between the thalamus and sensory and motor regions. There is also evidence for reduced intra-thalamic connectivity among people with schizophrenia. Thalamic connectivity abnormalities are present before the onset of a full psychotic illness, and severity has been found to predict conversion to a psychotic illness. There is an increasing appreciation for thalamic connectivity disturbances as representing a transdiagnostic feature present beyond the categorical bounds of schizophrenia. This growing literature includes evidence for deviations in thalamic connectivity among those with bipolar disorder, major depressive disorder, autism spectrum disorder, and obsessive-compulsive disorder (among others). Future research is needed to clarify the extent to which aspects of thalamic dysconnectivity, and their corresponding behavioral and clinical correlates, are specific to schizophrenia versus relevant across psychopathologies. Such knowledge can then inform the development of novel treatments aimed at the functional consequences of thalamic connectivity abnormalities.
Concluding Thoughts
Authors: Usrey W. Martin , Sherman S. Murray 
Published: November 2023

Abstract
This chapter discusses issues of thalamocortical relationships and functioning. It examines the general properties of thalamocortical relationships, which involve driver and modulator glutamatergic inputs, feedforward and feedback circuits, and burst and tonic firing modes. Moreover, the thalamus, cortex, and their interactions are the result of an extensive period of evolution since the earliest vertebrates to evolve had little more than spinal circuitry to control movements. The chapter also provides an overview of an evolutionary perspective on trans-thalamic pathways. It presents some key questions to consider when understanding the significance of the thalamus and the functional relationships between the thalamus and cortex.
Psychosis across place: The madding crowd—urban living and psychosis
Authors: Mollaahmetoglu Ozden Merve , Kirkbride James B. 
Published: November 2023

Abstract
This chapter discusses the changing demographics across the Global South, with an increase in urban living. It examines associations between exposure to urban life and incidence rates of psychotic disorders. The scope ranges from local to global, and the lens attempts to be both descriptive and critical. It reviews the historical and contemporary evidence for variation in incidence rates, goes on to consider major limitations of epidemiological research and the extent to which this supports a causal association between place and psychosis, and finally balances the available evidence in the context of public mental health and whether prevention strategies are viable.
Psychosis across persons 3: Genes, biology, and neurodevelopment
Authors: Segre Giulia , Iyegbe Conrad , Tosato Sarah , Busatto Geraldo , Dazzan Paola 
Published: November 2023

Abstract
The general understanding of the aetiology of psychoses has advanced in recent years, and the broad consensus is that psychoses emerge as a consequence of complex interactions between genes, other biological factors, and environmental factors. This chapter reviews current evidence specifically on genes and other biological risks and mechanisms. In the context of this book, what is most notable is that most—in fact, almost all—of the evidence is derived from studies conducted in select centres in a few high-income countries (e.g. the US, parts of western Europe) with next to no evidence from the Global South. Thus, while the existing evidence points to a complex and dynamic pathophysiological model of psychosis, there is clearly much to be learned by expanding research to a greater variety of populations across the world.
Ethiopia
Authors: Hanlon Charlotte , Cohen Alex , Alem Atalay 
Published: November 2023

Abstract
This chapter presents a brief summary of the research about psychosis that has been conducted in Ethiopia. As important as this research might be, the work in Ethiopia is most distinguished by how it has developed from a focus on epidemiological research to research to inform treatments and interventions, especially for individuals with psychosis. Furthermore, it must be noted that, at first, the research was conducted by a small cadre of Ethiopians who, over time, encouraged and mentored junior researchers who eventually took on the conduct of the projects and trials. Ethiopia now has a large number of mental health researchers who are carrying out important programmes to improve the lives of individuals with psychosis.
Chennai, India
Authors: Thara Rangaswamy , John Sujit , Padmavati Ramachandran , Mohan Greeshma , Raghavan Vijaya 
Published: November 2023

Abstract
This chapter provides a snapshot of research on psychotic disorders conducted at the Schizophrenia Research Foundation (SCARF) in Chennai, India over the past 3 decades. This includes studies on phenomenology, epidemiology, genetics, course and outcome, community-based interventions, stigma, and the role of work in the lives of persons with schizophrenia. In summarizing this work, the chapter reflects on the highs and lows of research in low-and-middle-income countries and the challenges encountered in conducting community research in low-resource settings. The common elements of the programme were case management with social and vocational rehabilitation, educational and awareness programmes for family and local community, income generation, and training in basic skills. It concludes with a section on priorities for future research and programme development in the Indian context.
Future directions
Authors: Roberts Tessa , Cohen Alex , Morgan Craig 
Published: November 2023

Abstract
This chapter recapitulates the issues with the majority of research on psychotic disorders being based primarily in high-income settings in the Global North. The absence of evidence from whole regions such as the Middle East severely limits our understanding. This lack of evidence from most of the world not only creates important limitations for the development of evidence-based services and policy, but it also means our assumptions about incidence, prevalence, risks, and short- and long-term course and outcome, must be tested in more diverse settings. This is essential if locally relevant systems of care and interventions are to be developed and implemented. Several challenges to achieving this goal remain. This chapter presents five major pillars that should be considered when gathering data in future research on psychoses.
Research in intellectual disability across cultures
Authors: Tromans Samuel J. , Munir Kerim , Langdon Peter E. , Alexander Regi T. 
Published: November 2023

Abstract
There has been limited research on the interaction between intellectual disability (ID) across cultures, particularly in minority groups with distinct cultural identities, and especially among those residing within low- and middle-income countries. Little is known about how the prevalence of ID compares across cultural groups, though this knowledge is essential for resource allocation. There is also a need to recognize cultural biases within major diagnostic criteria, as well as availability of adapted assessment tools, and therapeutic approaches. People with ID may experience barriers to accessing support services, and healthcare organizations have a duty to proactively address such barriers. Furthermore, perspectives on ID prevalent in certain cultures have a marked influence on not just people with ID, but also for those who care for them. Finally, people with ID need to be actively involved at all stages of cultural psychiatry research.
Anthropology and intellectual disability
Authors: McKearney Patrick , Zoanni Tyler 
Published: November 2023

Abstract
Anthropology’s methodological innovations enable us to get closer to the experiences, lives, and self-narrations of individuals categorized as having intellectual disabilities. Moreover, anthropology approaches intellectual disability from a cross-cultural perspective in order to facilitate better understanding of how the condition varies (and what it is affected by) in different societies. In doing so, it contributes significant missing pieces to the psychiatric puzzle of just how and why people become intellectually disabled—enabling us to reflect more deeply on the relationship between biological and social factors. Anthropology’s perspective (particularly on societies where ‘intellectual disability’ is not an important category) also reveals the particularity of the cultural conditions that support the psychiatric categorization of intellectual disability in the first place; as well as its limitation in framing the lives of such individuals in other contexts and in other aspects of their lives. This gives us deeper insight into what it is like to live as someone classified as intellectually disabled, as well as what such classifications leave out about them as rich, rounded, and feeling humans.
Sexuality, marriage, and parenthood across cultures
Authors: Tharian Priyanka , Thomas Lucretia , Vaidya Ratnaraj , Kapugama Chaya 
Published: November 2023

Abstract
This chapter elucidates some of the key themes in sexuality, marriage, and parenthood for individuals with intellectual disability (ID): historical context, attitudes of parents and carers, lesbian, gay, bisexual, and transgender people with ID, forced marriage, and parenthood. Sexuality, marriage, and parenthood are core elements of the human condition, as enshrined in the United Nations Declaration of Human Rights, and highlighted further in the United Nations Convention on the Rights of Persons with Disabilities. However, these rights have historically been overlooked for people with ID and, in some cases, actively targeted. This is relevant for clinicians working in the psychiatry of ID in terms of balancing the rights of individuals with the clinical responsibilities to ensure the safety and well-being of individuals with ID. The contents of this chapter provide both context and evidence-based information with regard to providing holistic care for people with ID.