Brain studies
3/8/2013
Bjornsdotter et al. 2009
Bystrova, 2009
confirms the c-afferent pathway for pleasant human touch See below
The recently discovered low threshold unmyelinated C-afferents that are
exquisitely sensitive to light, slow, gentle touch because it produces pleasure,
so the C-afferents play a role in growth too, and these same C-afferents also
reduce pain. The C-afferents constitute the second tactile system; the first
tactile system is large myelinated tactile A- afferents (pg. 144). C-afferents are
in the hairy skin, not the glabrous skin of the elbow, palm, etc. C-afferents
convey pleasure, no pain, no temperature, itch or tickle. The C-afferents go to
the insular cortex but not the somatosensory areas which are served by
myelinated tactile A-afferents
Warmth conveyed to the skin is a pleasant experience as this message is sent to
the limbic area of the brain, seat of emotional, affiliative, love behaviors, and
where hormonal responses (i.e. oxytocin) originate – not on kc bib yet
FT, Review of Birth KC breastcrawl effects. Says Oxytocin also stimulates the
amygdala so that the mother is imprinted with details of her newborn and begins
bonding. (pg. 300).
PT, Brain connectivity improves in the KC group compared to preterms without KC
and full terms without KC.
Direct interpersonal contact is processed differently in the brain from similar soft
touch applied through inanimate objects. You cannot get same response to KC
when there is a cloth, bra, or any inanimate object across the chest surface rather
than skin-to-skin. Massage is better than just touch.
Craig et al., 2000
Henderson 2011
Kaffashi et al.,2013
Kress et al., 2011
Lindgren et al., 2011
Loken et al., 2009 See below
Meek & Huertas, 2012
Morgan et al. 2011
Olausson et al.,2002
Olausson et al., 2010
Scher et al. 2009
Schneider et al., 2012
Wood, 2012
Adult descriptive study showing that human skin-to-skin contact with or
without movement (massage) are potent pleasant sensations (massage
is more potent than contact alone) and that these sensations activate
the pregenual anterior cingulated cortex, an area of the brain that
reduces pain, anxiety, stress and increases sense of well-being.
THIS IS PAIN REVIEW THAT TALKS ABOUT FABRIZI work on how mom
can really change the brain’s pain and eradicate memory and
neuropathways for pain in ways that sucrose and other non=maternal
touch interventions can.,
FT, 2 day old infants studied by HRV when sleeping with Mom in KC vs in
cot. Less stress when with mom.
Adults. Human hairy skin has dual tactile innervation: fast conducting myelinated
A-afferent fibers, and slow conducting unmyelinated (C) afferents that respond to
light, caressing touch
The physiology of the c-afferents that KC’s skin to-skin contact stimulate. Need 3
centimeters of exposure to be activated, they are exquisitely sensitive to pleasing
touch only and travel to the insular cortex for pleasant memories.
PT, RCT, brain complexity and maturation improved in KC group so that it was
better than preterms without KC group and nearly same as fullterms without KC at
term age.
PT, 16 yr follow up of RCT subjects from Charpak 1998 and 2001. KC definitely
improved connectivity, synaptic plasticity, and brain development of motor
functions (Kangaroo Care rescued these functions because given at a time when
brain was receptive to this stimulation and formulated pathways for these brain
functions.
PT, a review of the Schneider’s article for PsychCentral newsletter.
Related Studies:
Björnsdotter M, Morrison I, Olausson H.(2010). Feeling good: on the role of C fiber mediated touch in
interoception. Exp Brain Res. 2010 Dec;207(3-4):149-55. doi: 10.1007/s00221-010-2408-y. Institute for
Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden. malin.bjornsdotter@neuro.gu.se The
human skin is innervated by a network of thin, slow-conducting afferent (C and Aδ) fibers, transmitting a diverse
range of information. Classically, these fibers are described as thermo-, noci- or chemoreceptive, whereas
mechanoreception is attributed exclusively to thick, fast-conducting (Aβ) afferents. A growing body of evidence,
however, supports the notion that C tactile afferents comprise a second anatomically and functionally distinct
system signaling touch in humans. This review discusses established as well as recent findings which highlight
fundamental differences in peripheral and central information coding and processing between Aβ and C
mechanoreception. We conclude that from the skin through the brain, C touch shares more characteristics with
interoceptive modalities (e.g. pain, temperature, and itch) than exteroceptive Aβ touch, vision or hearing. In
this light, we discuss the motivational-affective role of C touch as an integral part of a thin-fiber afferent
homeostatic network for the maintenance of physical and social well-being.
Duffy studies too.
Fabrizi, L, Slater R, Wurley A. et al., (2011). A shift in sensory processing that enables the developing human brain to
discriminate touch from pain. Currents in Biology, 21: 1552-1558. Maternal touch is discriminated from anyone else’s
touch and maternal touch eradicates the memory and neural pathways leading to long termadverse effects of
repeated pain. (See other Fabrizi references in Related Literature on Pain).
Löken LS, Wessberg J, Morrison I, McGlone F, Olausson H. (2009). Coding of pleasant touch by unmyelinated
afferents in humans. Nature Neurosci. 2009 May;12(5):547-8. doi: 10.1038/nn.2312. Institute of Neuroscience and
Physiology, University of Gothenburg, Sweden. line.loken@neuro.gu.se Pleasant touch sensations may begin with
neural coding in the periphery by specific afferents. We found that during soft brush stroking, low-threshold
unmyelinated mechanoreceptors (C-tactile), but not myelinated afferents, responded most vigorously at intermediate
brushing velocities (1-10 cm s(-1)), which were perceived by subjects as being the most pleasant. Our results
indicate that C-tactile afferents constitute a privileged peripheral pathway for pleasant tactile stimulation that is
likely to signal affiliative social body contact.
McGlone, F & Reilly D. 2010. The cutaneous sensory system, Neuroscience Biobehav review. 34(2): 148-159. There
are four systems (pain, peripheral touch, thermal, and pruritic and now we add the c-afferent mechanoreceptor affective
system.
Milgrom J, Newnham C, Anderson PJ, Doyle LW, Gemmill AW, Lee K, Hunt RW, Bears M, Inder T. (2010) Early
sensitivity training for parents of preterm infants, impact on developing brain. Pediatr Res 67(3): 330-335. Taught
parents how to reduce infant stress and found Brain Maturation and Connectivity of white matter measured by
diffusion MRI by ADC (greater restriction) and FA (increase) were sig enhanced in treatment group . No differences
in brain volume or short term medical outcomes. Sensitivity training of parents in NICU is assoc. with improved
cerebral white matter micro-structureal development in preterm infants.
Morrison I, Löken LS, Minde J, Wessberg J, Perini I, Nennesmo I, Olausson H. (2011). Reduced
C-afferent fibre density affects perceived pleasantness and empathy for touch. Brain. 2011 Apr;134(Pt 4):111626. doi: 10.1093/brain/awr011.Department of Clinical Neurophysiology, Blå stråket 7, Sahlgrenska University
Hospital, S-413 45 Gothenburg, Sweden. india.morrison@neuro.gu.se
We examined patients with a heritable disorder associated with a mutation affecting the nerve growth factor beta
gene. Their condition has been classified as hereditary sensory and autonomic neuropathy type V. Carriers of the
mutation show a reduction in density of thin and unmyelinated nerve fibres, including C afferents. A distinct type of
unmyelinated, low-threshold mechanoreceptive C fibre, the C-tactile afferent, is present in hairy but not glabrous
skin of humans and other mammals. They have been implicated in the coding of pleasant, hedonic touch of the kind
that occurs in affiliative social interactions. We addressed the relationship between C fibre function and pleasant
touch perception in 10 individuals from a unique population of mutation carriers in Sweden. We also investigated
the effect of reduced C-fibre density on patients' evaluation of observed interpersonal touch (empathy). Results
showed that patients perceived gentle, slow arm stroking, optimal for eliciting C-tactile afferent responses (110 cm/s), as less pleasant than did matched controls and also differed in their rating patterns across
stimulation velocities. Further, patients' blood-oxygen-level-dependent responses in posterior insular cortex-a target for C afferents--were not modulated by stimulation optimal for activating C-tactile afferents. Hence,
perception of the hedonic aspect of dynamic touch likely depends on C-tactile afferent density. Closely similar
patterns between individuals' ratings of felt and seen touch suggest that appraisal of others' touch is anchored
in one's own perceptual experience, whether typical or atypical.
Morrison I, Löken LS, Olausson H. (2010). The skin as a social organ. Exp Brain Res. 2010 Jul;204(3):305-14.
doi: 10.1007/s00221-009-2007-y. Institute for Neuroscience and Physiology, Göteborg University, Göteborg,
Sweden. india.morrison@neuro.gu.se
In general, social neuroscience research tends to focus on visual and auditory channels as routes for social
information. However, because the skin is the site of events and processes crucial to the way we think about, feel
about, and interact with one another, touch can mediate social perceptions in various ways. This review situates
cutaneous perception within a social neuroscience framework by discussing evidence for considering touch (and to
some extent pain) as a channel for social information. Social information conveys features of individuals or their
interactions that have potential bearing on future interactions, and attendant mental and emotional states. Here, we
discuss evidence for an affective dimension of touch and explore its wider implications for the exchange of social
information. We consider three important roles for this affective dimension of the cutaneous senses in the
transmission and processing of social information: first, through affiliative behavior and communication; second, via
affective processing in skin-brain pathways; and third, as a basis for intersubjective representation.