Margaret Kennard (1899–1975): Not a ‘Principle’ of brain plasticity but a founding mother of developmental neuropsychology

Dennis, Maureen

doi:10.1016/j.cortex.2009.10.008

Cited by 56 publications

(28 citation statements)

References 82 publications

(75 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although not an absolute predictor of functional recovery (Kolb et al, 2000, Giza and Prins, 2006, Dennis, 2010), it has long been appreciated that juvenile brains are often more resilient to injury than mature brains (Broca, 1865, Kennard, 1936), however the underlying mechanisms for these profound differences in neuronal plasticity and functional recovery are just beginning to be understood.…”

Section: Discussionmentioning

confidence: 99%

Adult cortical plasticity following injury: Recapitulation of critical period mechanisms?

Nahmani

Turrigiano

2014

Neuroscience

View full text Add to dashboard Cite

A primary goal of research on developmental critical periods is the recapitulation of a juvenile-like state of malleability in the adult brain that might enable recovery from injury. These ambitions are often framed in terms of the simple reinstatement of enhanced plasticity in the growth-restricted milieu of an injured adult brain. Here, we provide an analysis of the similarities and differences between deprivation-induced and injury-induced cortical plasticity, to provide for a nuanced comparison of these remarkably similar processes. As a first step, we review the factors that drive ocular dominance plasticity in the primary visual cortex of the uninjured brain during the critical period (CP) and in adults, to highlight processes that might confer adaptive advantage. In addition, we directly compare deprivation-induced cortical plasticity during the CP and plasticity following acute injury or ischemia in mature brain. We find that these two processes display a biphasic response profile following deprivation or injury: an initial decrease in GABAergic inhibition and synapse loss transitions into a period of neurite expansion and synaptic gain. This biphasic response profile emphasizes the transition from a period of cortical healing to one of reconnection and recovery of function. Yet while injury-induced plasticity in adult shares several salient characteristics with deprivation-induced plasticity during the CP, the degree to which the adult injured brain is able to functionally rewire, and the time required to do so, present major limitations for recovery. Attempts to recapitulate a measure of CP plasticity in an adult injury context will need to carefully dissect the circuit alterations and plasticity mechanisms involved while measuring functional behavioral output to assess their ultimate success.

show abstract

Section: Discussionmentioning

confidence: 99%

Adult cortical plasticity following injury: Recapitulation of critical period mechanisms?

Nahmani

Turrigiano

2014

Neuroscience

View full text Add to dashboard Cite

show abstract

“…1, Models E-J). Because children with later-onset injury typically have some measured or historical information about pre-injury development, delayed effects (what Kennard identified as growing into a deficit, discussed in Dennis, 2010) can be identified, whereby deficits not apparent at the time of the injury emerge with increasing time since injury, or as the brain matures (Luciana, 2003). Functional outcome is measured by Intercepts 1 and 2, and Slope 3, but also by indices of the effect of acquired lesion on loss and recovery of previously developed skills and new skill development.…”

Section: When To Assessmentioning

confidence: 99%

Functional Plasticity in Childhood Brain Disorders: When, What, How, and Whom to Assess

et al. 2014

Self Cite

View full text Add to dashboard Cite

At every point in the lifespan, the brain balances malleable processes representing neural plasticity that promote change with homeostatic processes that promote stability. Whether a child develops typically or with brain injury, his or her neural and behavioral outcome is constructed through transactions between plastic and homeostatic processes and the environment. In clinical research with children in whom the developing brain has been malformed or injured, behavioral outcomes provide an index of the result of plasticity, homeostasis, and environmental transactions. When should we assess outcome in relation to age at brain insult, time since brain insult, and age of the child at testing? What should we measure? Functions involving reacting to the past and predicting the future, as well as social-affective skills, are important. How should we assess outcome? Information from performance variability, direct measures and informants, overt and covert measures, and laboratory and ecological measures should be considered. In whom are we assessing outcome? Assessment should be cognizant of individual differences in gene, socio-economic status (SES), parenting, nutrition, and interpersonal supports, which are moderators that interact with other factors influencing functional outcome.

show abstract

“…This idea arose in part from misreading of Kennard’s work in the 1930s and 1940s (see Dennis, 2010). Kennard had shown that age, but also factors other than age, predicted outcome after early brain lesions.…”

Section: Introductionmentioning

confidence: 99%

Age, plasticity, and homeostasis in childhood brain disorders

Dennis¹,

Spiegler²,

Juranek³

et al. 2013

Neuroscience & Biobehavioral Reviews

Self Cite

View full text Add to dashboard Cite

It has been widely accepted that the younger the age and/or immaturity of the organism, the greater the brain plasticity, the young age plasticity privilege. This paper examines the relation of a young age to plasticity, reviewing human pediatric brain disorders, as well as selected animal models, human developmental and adult brain disorder studies. As well, we review developmental and childhood acquired disorders that involve a failure of regulatory homeostasis. Our core arguments are: Plasticity is neutral with respect to outcome. Although the effects of plasticity are often beneficial, the outcome of plasticity may be adaptive or maladaptive.The young age plasticity privilege has been overstated.Plastic change operates in concert with homeostatic mechanisms regulating change at every point in the lifespan.The same mechanisms that propel developmental change expose the immature brain to adverse events, making it more difficult for the immature than for the mature brain to sustain equilibrium between plasticity and homeostasis.Poor outcome in many neurodevelopmental disorders and childhood acquired brain insults is related to disequilibrium between plasticity and homeostasis.

show abstract

Margaret Kennard (1899–1975): Not a ‘Principle’ of brain plasticity but a founding mother of developmental neuropsychology

Cited by 56 publications

References 82 publications

Adult cortical plasticity following injury: Recapitulation of critical period mechanisms?

Adult cortical plasticity following injury: Recapitulation of critical period mechanisms?

Functional Plasticity in Childhood Brain Disorders: When, What, How, and Whom to Assess

Age, plasticity, and homeostasis in childhood brain disorders

Contact Info

Product

Resources

About