Behavioral vigilance following infusions of 192 IgG-saporin into the basal forebrain: selectivity of the behavioral impairment and relation to cortical AChE-positive fiber density

“In rodents, lesions of cholinergic inputs to the cortex impair tests of sustained attention, particularly across sensory modalities (McGaughy et al., 1996, 2002; Turchi and Sarter, 1997).”

“As orienting is not necessary for detection, the residual hit rate after cortical cholinergic deafferentation (McGaughy et al, 1996) may have been because of detections that occurred without the facilitating benefits of attentional orienting.”

“There is now ample experimental evidence in support of the hypothesis that the integrity of cortical cholinergic inputs is necessary for normal attentional performance, and that such performance robustly activates cortical cholinergic inputs [3,29,32,33,39, 50,73,101,99,132,162,183,180,181].”

“…or the selective removal of the cortical cholinergic input system indicated the necessary role of this neuromodulator for attentional performance (Chiba et al., 1995; Dalley et al., 2004; McGaughy et al., 1996, 2000, 2002; Muir et al., 1992, 1994; Turchi and Sarter, 1997; Voytko et al., 1994).”

“…system represents an essential component of neuronal systems mediating attentional functions and capacities (Chiba et al., 1995; Dalley et al., 2001; Everitt and Robbins, 1997; McGaughy et al., 1996; 2000, 2002; Mesulam, 1990; Sarter and Bruno, 1997, 2000; Sarter et al., 1999, 2001; Voytko, 1996).”

“In all studies, the degree of attentional impairment was correlated with the extent of cortical deafferentation (McGaughy et al., 1996; McGaughy and Sarter, 1998; McGaughy et al., 1999).”

“…from segregated populations in the central amygdala and the caudate nucleus (after Gielow and Zaborszky, 2017). selective attentional deficits, while sparing other cognitive functions such as learning and memory (Dalley et al., 2004; Gill et al., 2000; McGaughy et al., 1996; Voytko et al., 1994).”

“[65] McGaughy J, Kaiser T, Sarter M.”

“Neither methylphenidate nor AChEIs improved performance in normal or basal forebrain lesioned rats (McGaughy et al., 1996; McGaughy & Sarter, 1998; McGaughy et al., 1999).”

“Thus, lesions of the cholinergic neurons of the basal forebrain produced using excitotoxins or the more selective cholinergic toxin 192-IgG saporin result in robust and persistent impairments in sustained attention (Muir et al., 1994; Voytko et al., 1994; McGaughy et al., 1996).”

“Lesions of cholinergic BF neurons have been associated with decreased amplitude of theta and gamma activity (Lee et al., 1994; McGaughy et al., 1996; Gerashchenko et al., 2001; Berntson et al., 2002), yet not to the extent that non-specific lesions or inactivation of the total BF cell population had previously been sh…”

“It has been shown previously that a single injection of 192IgG-saporin results in a complete and selective loss of ChATimmunoreactive neurons in the basal forebrain, long-lasting cortical cholinergic hypoactivity, and deficits in attention, learning, and memory tasks (Berger-Sweeney et al., 1994; Heckers et al., 1994;…”

“…the neurochemical basis of attention have found that both norepinephrine (NE) and acetylcholine (ACh) mediate aspects of attention (McGaughy and Sarter, 1995b; McGaughy et al., 1996; Rajkowski et al., 2004; Milstein et al., 2007) but some conditions dissociate the functions of these systems.”

“…demonstrated that the selective loss of corticopetal cholinergic projections is sufficient to produce impairments in attention (Chiba et al., 1995, 1999; Bucci et al., 1998), especially in sustained (McGaughy et al., 1996; McGaughy and Sarter, 1998) and divided attention (Turchi and Sarter, 1997).”

“Several lines of evidence, including in vivo measures of cortical ACh release in task-performing animals [225] and investigations of the cognitive effects of lesions of this system [166], collectively suggested a crucial role of cortical ACh in the detection and selection of relevant stimuli and in the capacity to sub…”

“Infusions of this cholinotoxin into the nbM/SI or cortical regions results in persistent and robust deficits in attentional performance, specifically impairing animals’ ability to detect cues indicative of reward (McGaughy et al., 1996; McGaughy and Sarter, 1998; Turchi and Sarter, 1997, 2000).”

“This circuit includes cholinergic neurons in the basal forebrain region of the nucleus basalis of Meynet (nbM) that project to the cortex (McGaughy et al., 1996; Sarter et al., 2001).”

“Conversely, silencing cholinergic activity reduced hit rates to long cues, consistent with effects of cholinergic lesions (9).”

“Similarly, using an operant task designed to measure sustained attention performance, McGaughy et al. (1996) demonstrated that the loss of cortical cholinergic inputs produced by infusions of the selective cholinergic immunotoxin 192 IgG-saporin into the basal forebrain decreases animals’ ability…”

“Using this approach, McGaughy et al. (1996) found that selective cholinergic deafferentation of cortex, by infusing 192 IgG-saporin into the nucleus basalis/substantia innominata of the basal forebrain, of rats previously trained on the SAT elicited selective deficits in stimulus detection.”

“Lesions of corticopetal cholinergic projections (from the NBM) also often impair performance on a variety of attentional tasks (McGaughy et al. 1996, 2002; Lehmann et al. 2003) without substantially affecting memory (e.g., Baxter et al. 1995; Dornan et al. 1996; Galani et al. 2002).”

“Most of the studies report disrupted attentional processing in NBor MS-injected animals (McGaughy et al. 1996; Wrenn andWiley 1998), thus confirming the role of the cholinergic system in attention.”

“This operant procedure consists of a random sequence of signal and nonsignal events followed by a variable intertrial interval (ITI), as described in detail by McGaughy et al. (1996).”

“For example, 192-IgG-saporin-mediated lesion of cholinergic neurons impaired the ability of rats to discriminate between signal and non-signal visual events in an attention task (McGaughy et al., 1996) and disrupted training-induced cortical map reorganization associated with motor learning”

“Cholinergic inputs to frontoparietal cortex have been associated with performance on sustained and selective attention tasks (McGaughy et al., 1996; Himmelheber et al., 2001), with attention-correlated-neural activity (Gill et al.”

“The present results, taken together with other data (Muir et al., 1994; Chiba et al., 1995, 1997; McGaughy et al., 1996), indicate that specific deficits in attentional processing result from selective destruction of basal forebrain cholinergic neurons.”

“…the selective decrease in the animals' ability to detect signals (i.e., hits) that results from lesions of the cortical cholinergic input system (McGaughy et al. 1996; McGaughy and Sarter 1998), from infusions of a BZR agonist or an NMDA receptor antagonist into the BF (Holley et al. 1995;…”

“Cholinergic activity is necessary for the performance of attention tasks (e.g., McGaughy et al , 1996; for review see Sarter et al., 2005, 2006).”

“The detection of cues in attentional contexts depends on cholinergic activity in the cortex (McGaughy et al., 1996).”

“For example, selective loss of cortical cholinergic inputs, produced by infusions of 192 IgG-saporin into the basal forebrain or the cortex, results in impairments in a wide range of attentional abilities, ranging from sustained attention to divided attention [110,206].”

“Earlier work has shown that increases in cortical cholinergic neurotransmission enhance the selectivity of perceptual processing (Furey et al, 2000; McGaughy et al, 1996; McGaughy and Sarter, 1998; Sarter et al, 2005), and improve the efficiency (reduce activation) of brain regions supporting…”

“For example, cortical release of acetylcholine is greatest during demanding attention tasks [74] and cholinergic SI neurons have been shown to play a role in sustained [75] and divided attention [76] in rats.”

“Histological analyses DBH-positive fibers were quantified in cortical areas in a manner modified from that described by McGaughy et al. (1996).”

“Cholinergic drugs modulate attentional performance and the activity of brain regions mediating attention (McGaughy et al., 1996; Turchi and Sarter 1997; Arnold et al., 2002; Sarter et al., 2005; Kozak et al., 2006, 2007; Bentley et al., 2008; Furey et al., 2008; Deco and Thiele, 2009).”

“…(ACh) in cortex results in arked performance deficits in tasks explicitly designed to ax attentional processing (McGaughy and Sarter, 1998; cGaughy et al., 1996, 2002; Turchi and Sarter, 1997). oreover, performance in such tasks is sufficient to stimulate ortical ACh release (Arnold et…”

“Because of evidence indicating that cortical ACh release mediates attentional performance (McGaughy et al., 1996; Gill et al., 2000; Dalley et al., 2004; Apparsundaram et al., 2005; Sarter et al., 2005, 2006; Kozak et al., 2006; Parikh et al., 2007), the enhancement of attentional functions and capacities by nAChR ago…”

“Despite being tethered while performing the SAT, rats exhibited typical levels of performance.”

“Following the validation of the immunotoxin 192-IgG-saporin as a tool for selectively removing the cortical cholinergic input system [62], several experiments demonstrated that such deafferentation selectively impairs the detection of signals in the SAT and similar tasks [63,64].”

“…systems and other variables (e.g., gonadal steroids) in signal detection and vigilance (Briand et al., 2008; McGaughy & Sarter 1995, 1998, 1999; McGaughy et al., 1996; 1997,1999, 2000; Turchi et al.,1995, 1996; Turchi & Sarter 2001a,b; Himmelheber et al. 2000a,b, 2001; Holley et al., 1995;…”

“Cholinergic lesions disrupt sustained, selective and divided attention performance (Bucci et al., 1998; Dalley et al., 2004; McGaughy et al., 1996) and impair performance involving ns in the intact brain (a), and following the dual loss of basal forebrain cholinergic neurons d to provide a…”

“Such selective lesions of the BF cholinergic system were repeatedly demonstrated to result in a decrease in the animals' ability to detect a range of visual signals but not to affect their conditioned response to nonsignal trials (e.g. McGaughy et al., 1996; McGaughy & Sarter, 1999).”

“, 2016) demonstrated that cholinergic transients cause behavior: optogenetic inhibition of transients during signal trials reduced hits, but did not affect correct rejections, similar to the effects of cholinergic lesions (McGaughy et al., 1996).”

“One of the primary functions of the cholinergic septohippocampal projection is attention, including vigilance, arousal, and expectancy (McGaughy et al., 1996; Muir, 1997; Baxter et al., 1997).”

“Rats were randomly assigned to receive the immunotoxin 192 IgGsaporin (Advanced Targeting Systems, San Diego, CA) or its vehicle, Dulbecco's saline infused into the region of the entorhinal cortex, using previously published surgical techniques (McGaughy et al., 1996).”

“…are known to be preferentially sensitive to cholinergic lterations in the basalo-cortical system (e.g., Harati et al., 008; Lehmann et al., 2003; McGaughy et al., 1996, 2002) nd the decline of attention processes with age may be related, t least partially, to a neuronal loss/dysfunction in this…”

“…of the frontal– parietal cholinergic system via drug or deafferentiation has dramatic effects on performance and interacts with the distractor (e.g., McGaughy et al., 1996; Parikh et al., 2007; Broussard et al., 2009; Howe and Sarter, 2010), suggesting that while performance-and challenge-related…”

“Similar floor effects at shorter signal durations following an attentional challenge were previously reported on this task in rats (e.g., McGaughy et al., 1996;Kozak et al., 2006), suggesting the 500 ms duration may be the most useful to examine when considering manipulations that decrease hit…”

“…may however, wonder whether the AChE-staining technique is specific enough to account for cholinergic denervation, particularly in the medial prefrontal, cingulate and retrosplenial cortices (see studies based on this method; Holley et al., 1994; McGaughy et al., 1996; Turchi & Sarter, 1997, 2000).”

“Contrasting effects on release were found in animals performing a task, which taxes attentional functions and is known to depend on the integrity and activity of the cortical cholinergic input system (Arnold et al, 2002; McGaughy et al, 1996 ).”

“to guide decisions about ongoing behavior (Muir et al., 1992; McGaughy et al., 1996; Turchi & Sarter, 1997; Dalley et al., 2004; Botly & De Rosa, 2009).”

“…the systemic scopolamine data, it might be concluded that set-shifting is not regulated by central acetylcholine, based on the absence of cholinergic lesion effects on attentional set-shifting relative to impairments in other aspects of attention following such lesions (e.g. McGaughy et al., 1996).”

“The 5-CSRTT and the SATwere originally developed for rats and are well-validated based on a wealth of data examining its behavioural, neural and pharmacological underpinnings (Carli et al. 1983; McGaughy et al. 1996; Lustig et al. 2013).”

“Similar observations have beenmade in rats with cortical cholinergic lesions (McGaughy et al., 1996; Sarter et al., 2001).”

“These ®ndings are also in accord with previous studies that report behavioural effects of intrabasalis 192 IgG-saporin only after fairly extensive cholinergic degeneration (McGaughy et al., 1996).”

“Other research demonstrates a role for the BF cholinergic system in the regulation of attentional processes engaged in sustained or selective attention tasks (Muir et al., 1992; Pang et al., 1993; Voytko et al., 1994; McGaughy et al., 1996; Chiba et al., 1999).”

“Indeed, previous studies have indicated that the basal forebrain cholinergic system becomes most relevant in tasks in which attentional load is increased (McGaughy et al., 1996; Turchi and Sarter, 1997).”

“Sustained attention (simple reaction time) Sustained attention was assessed using modifications of previously published procedures (McGaughy & Sarter 1995; McGaughy et al. 1996, 1997; McDonald et al. 1998; McGaughy & Sarter 1999).”

“For example, accuracy of visual signal detection is decreased in attention-demanding tasks following loss of basal forebrain corticopetal cholinergic neurons (McGaughy et al., 2002, 1996).”

“The go/no-go task is a variation of the signaldetection paradigm that is used commonly to assesses both sustained attention (vigilance) and impulsivity in humans (Zahn et al. 1980, 1991) and animals (McGaughy and Sarter 1995a,b; McGaughy et al. 1996, 1997).”