SENSORY SYSTEMS, Apuntes de Psicología

¡Descarga SENSORY SYSTEMS y más Apuntes en PDF de Psicología solo en Docsity! LESSON 10 & 11 SENSORY SYSTEMS II. INTRODUCTION TO THE SENSORY SYSTEMS Kora-Mareen Bühler kobuhler@ucm.es Psychobiology Laboratory Complutense University Madrid Learning objectives II. INTRODUCTION TO THE SENSORY SYSTEMS 1. How physical or chemical energy is converted into neuronal communication. 2. Sensory receptors and pathways How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS Sensation: registration of a physical stimuli from the environment by the sensory organs. Simple action Perception: the subjective experience of sensation (interpretation). Complex action influenced by context, emotional states, past experiences,… How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS Sensory stimulus Sensory transduction Modification of the action potential Generation of an action potential The action potential is transmitted through a peripheral nerve to the spinal cord or through a cranial nerve to the encephalon Sensitive pathways of the CNS How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS Receptor density (determinates sensitivity) How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS Receptor fields: region of space in which the presence of a stimulus will alter the firing of a neuron. How physical energy is converted into neuronal communication II. INTRODUCTION TO THE SENSORY SYSTEMS Different neurons involved. Different levels of discharge in the same neuron. The information is processed by distinct regions of the thalamus and cortex. SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS VISUAL STIMULUS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS VISUAL STIMULUS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CELULAR STRUCTURE OF THE RETINA SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CELULAR STRUCTURE OF THE RETINA SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS PHOTORECEPTORS Photopic vision • Cones • Well-lit conditions • Color perception • High visual acuity (clarity) Scotopic vision • Rods • Low light conditions • Lack of detail and color SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY STIMULUS Objects vibration Motion of molecules of air (condensation and rarefraction) Sound waves Sound (vibration range between 30 and 20.000 waves per second are detectable) SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY STIMULUS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY STIMULUS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY RECEPTORS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY RECEPTORS https://www.youtube.com/watch?v=v9gYwP62 K1Y SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS AUDITORY RECEPTORS SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS Auditory pathway SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: TASTE SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: TASTE Stimulus: Salty and sour: positive ions (NaCl, H+) Bitter: alkaloids (quinine) Sweet: sugars (glucose, fructose) Umami: aminoacids (monosodium glutamate) SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS TASTE RECEPTORS Taste cells are modified epithelial cells that function as receptors. Taste cells contain the taste hairs that are the portions sensitive to taste. These hairs protrude from openings called taste pores. SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS TASTE RECEPTORS There are two opposing views of how taste qualities are encoded in the periphery. a, In the labelled-line model, receptor cells are tuned to respond to single taste modalities — sweet, bitter, sour, salty or umami — and are innervated by individually tuned nerve fibres. In this case, each taste quality is specified by the activity of non-overlapping cells and fibres. b,c, Two contrasting models of what is known as the 'across-fibre pattern'. This states that either individual TRCs are tuned to multiple taste qualities (indicated by various tones of grey and multicoloured stippled nuclei), and consequently the same afferent fibre carries information for more than one taste modality (b), or that TRCs are still tuned to single taste qualities but the same afferent fibre carries information for more than one taste modality (c). In these two models, the specification of any one taste quality is embedded in a complex pattern of activity across various lines. Recent molecular and functional studies in mice have demonstrated that different TRCs define the different taste modalities, and that activation of a single type of TRC is sufficient to encode taste quality, strongly supporting the labelled-line model. Chandasshekar et al., 2006. Nature. SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS TASTE TRANSDUCTION Salty and sour: enter directly into the receptor cell through ion channels Bitter, Sweet, Umami: attach to metabotropic (G-protein coupled receptors) on the surface of the receptor cell SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: OLFACTION SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: OLFACTION SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: OLFACTION SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: OLFACTION Stimulus: Odorants: most are volatile substances of organic origin. Different odorants attach to different receptor molecules SENSORY RECEPTORS AND PATHWAYS II. INTRODUCTION TO THE SENSORY SYSTEMS CHEMICAL SENSES: OLFACTION Olfactory pathway